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phd placeholder: "Decentralized Machine Learning Systems for Information Retrieval" #7290

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synctext opened this issue Feb 10, 2023 · 56 comments
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@synctext
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synctext commented Feb 10, 2023

< Placeholder >
timeline: April 2023 - April 2027.

Key historical 2016 issue of thesis topic

ToDo: 6 weeks hands-on Python onboarding project. Learn a lot and plan to throw it away. Next step is then to start working on your first scientific article. You need 4 thesis chapters and you then completed your phd.

One idea: towards trustworthy and perfect metadata for search (e.g. perfect memory retrieval for the global brain #7064 ).
Another idea: Gradient decent model takes any keyword search query as input. Output is a limited set of vectors. Only valid content is recommended. Learning goal is to provide semantic matching between input query and output vector.
General background and Spotity linkage possible dataset sharing

Max. usage of expertise: product/market fit thinking

Background reading:

Venues:

Possible scientific storyline: SearchZero a decentralised, self-supervised search engine with continuous learning

@mg98
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mg98 commented Apr 24, 2023

Ideas...

  • "Perfect search" as an instance of unsupervised online learning-to-rank (OL2R) (using deep neural networks). The ML model should use user signals (i.e., clicks/downloads) as a measure to learn query-document relevancy and accordingly adapt its weights.
    • I think the employment of NN makes sense as we have very limited metadata/understanding about each torrent, much unlike is the case with web pages
    • State-of-the-art for OL2R: Duel Bandit Gradient Descent (DBGD) (listwise approach), (placeholder)
    • Potential research lines:
      • Analysis of pointwise, pairwise, & listwise OL2R approaches for their application on distributed or decentralized systems; How do the tradeoffs added by listwise approaches scale with the constraints of robustness and efficiency in a dist./dec. network? Or more specific: how would DBGD work out in this setting?
      • Alternatively, ...
        • Decentralized AI-powered information retrieval using something as simple as, e.g., BM25 ranking (that is, without NN)
        • Decentralized embeddings for semantic search

@synctext
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synctext commented Apr 26, 2023

Brainstorm: We present a decentralised search engine, based on deep learning of URLs, URIs, magnet links, and IPFS links. Deep learning has been successfully used in the past to identify trusted and malicious websites. We go beyond this prior work and present an experimental search engine based on fully decentralised unsupervised learning. Our fuzzy search algorithm is based on unsupervised online learning-to-rank (OL2R).
Left for future work: beyond static item list (no content discovery, currently unable to add new content items), reputation & trust for spam filtering (also required for trustworthy content discovery).

Literature, Dataset and code:

@mg98
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mg98 commented May 2, 2023

Spent the last week doing basic courses on neural networks again. Trying to get a linear regression model running to predict a sine function (using SGD). As basic as this is, implementing it is not as easy as I would have expected 🥲
EDIT: Probably because a sine function is not exactly linear 🤦🏼‍♂️

I will continue to try to get it to work. I need to learn it at some point, I think. However, I'm inclined to first-publication ideas that do not directly employ NN/learning, as kind of a soft start.

Talked to @kozlovsky again about semantic search based on simple embeddings. We could use the crowdsourced information and metadata to compute embeddings for every torrent and build a distributed (dec.) search algorithm based on vector distance to have a YouTube-like search experience.
I don't know how far the literature is with that but I feel like there are some interesting avenues to explore:

  • The language model used for vectorization: How to distribute it? Or should it come shipped with the software? How to ensure correctness/consistency. I imagine we'd have to reach consensus somehow over the computation of an embedding.
  • How static is the language model really... thinking about decentralized fine-tuning and its challenges
  • With a distributed database of vectors, how do you efficiently search the network by cosine similarity (as opposed to text-matching)? This might as well be trivial; I'm just brainstorming here.

Use this as a basis for semantic search and improve through OL2R in the next step?

This week's ToDos:

  • Finish my mini-project of a NN that is able to predict a sine function
  • Explore collaborative filtering, recommender systems
  • Explore information retrieval on knowledge graphs

@synctext
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synctext commented May 3, 2023

Please chat to all people in the lab, understand their speciality. btw documenting your lesson learned; ML blogs make it look easy, none of them worked.

Please review the Meerkat system Github repo from RedPajama.

Suggested sprint: you successfully encoded sin(). Next, take 4 images, try to embed them in a machine learning model using useful overfitting. Meerkat docs example of embed(). Scientific primitive, unbounded storage of unstructured data for decentralised learning. Key question, how much storage space for 1 million static thumbnails?

import meerkat as mk
mk.search(
    df, 
    query=mk.embed("A photo of a person", engine="clip"),
    by=mk.embed(df["image"], engine="clip")
)

@mg98
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mg98 commented May 8, 2023

Got a sine function prediction working using a NN regression model. It's not much... but feels good to have succeeded at this task. Learned about activation functions, and the challenge of parametrization in ML.

Also did some reading on tagging, recommender systems, and collaborative filtering, which opens another broad area of research, e.g., the issue of trust in collaborative tagging (see research topic 4 in science#42) - which I do find interesting.
Publication idea: Empirical analysis/ measurements of MeritRank deployed on Tribler

This (and perhaps also the next) week, I want to play around with Meerkat, learn about Autoencoder, and see if I can get something up and running, i.e., another ML model. I hope to further evolve my understanding of AI/ML and learn about yet new concepts.

@synctext
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synctext commented May 12, 2023

Rich metadata embedding of "artist passport" Cullah.
Cullah donation wallet 1FfnfPJJ6yTTT9PGZe8TGgfEGQFc9kvQoW
Linkage with strong identity and GoldEuro direct donation by superfans.

scientific venue https://dl.acm.org/conference/facct

@mg98
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mg98 commented May 13, 2023

Update on Autoencoder:

The hardships of the last weeks seem to start paying off. I was able to create some functional autoencoders within just one day.

I trained a model on eight pictures displaying tulips (dimensions: 240x180px), i.e., an input layer of 3x240x180=130k neurons, reduced that to 1000 neurons in a single hidden layer (encoding). If I'm not mistaken, this equates to a data reduction from 130 to 4 KB (the original JPEGs had 50-80 KB).

Example decoded output:
Screenshot 2023-05-09 at 15 28 14

This might not be impressive, and with the right parametrization, we might be able to get more out of it. But for now, I'm just happy that it works in principle.

@mg98
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mg98 commented May 22, 2023

Motivated by my recent success with autoencoders, I spent the last week trying again to get a pairwise LTR model for a sample of test data running. By doing that, I learned a lot more about the details of this approach. However, I had to pause this project because I would like to move this outside of a notebook and run it locally. I'm waiting for my work MacBook for that (my machine has difficulties) - it should arrive next week.

So now I turned to the idea of NN-based file compression which apparently is not only successful with the task of lossless compression but can actually compete with traditional algorithms like GZIP or 7Z (see, e.g., DZIP or its successor DeepZIP).
I find that quite impressive and as I have in the past been working in the realm of data deduplication and also compression a bit, I'm interested to understand how that works, how much of it is theory, and how much of it can actually sustain real-world use cases.
They do employ autoencoders but also recurrent NNs. RNNs are yet new to me and I've come across them before in the context of language models, so I want to educate myself on them finally and thereby further broaden my knowledge of AI/ML.

@synctext
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synctext commented May 31, 2023

Using LLM for ranking. Background https://blog.vespa.ai/improving-text-ranking-with-few-shot-prompting/ and also https://blog.reachsumit.com/posts/2023/03/llm-for-text-ranking/ Did a silly OpenAI experiment, might be useful building block, but small part:

These are examples of queries with sample relevant documents for
each query. The query must be specific and detailed.

Example 1:
document: ubuntu-mate-19.10-desktop-amd64.iso
query: latest Ubuntu image

Example 2:
document: ubuntu-21.10-beta-pack
query: ubuntu 21.10

Example 3:
document: chemistry-3b-002-fall2014-ucberkeley
query: chemistry class Berkeley

Example 4:
document: 14BHD 2020-2021 Informatica
query:

Found this dataset with 7000+ pet images (+ code) for scientific research, so it sort of works 🐶

@mg98
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mg98 commented Jun 2, 2023

So I ended up not learning about RNNs, NN-compression, etc. last week.

Instead, I investigated an idea proposed by @grimadas, which is to leverage ML as a means to classify nodes as Sybil or not-Sybil and use the resulting score as a weight-factor in the reputation algorithms of MeritRank.
The way this would work is by embedding nodes using algorithms like node2vec (excellent tutorial series) such that in vector space they reveal information about structure and connectivity of individual nodes, off which patterns can be derived or learned that could identify Sybil-regions. Further, an ML model would be trained on the simulation of Sybil attacks (cycle, serial, series). The hope is that the model will find more effective strategies to mitigate Sybil attacks than the static heuristics employed in MeritRank.
In a first short literature review, I have only found efforts of ML for Sybil detection/tolerance in the context of online social networks.


Back to LTR

Got my new MacBook yesterday 🔥 so I was able to continue my work on the OL2R project. My goal was to just get anything working, and I specifically sticked with the pairwise LTR approach for this. To this end, I was only following the basic idea, which is to train a model based on query-document-pair triples, and followed my intuition for the rest.

Algorithm

  • I use a truncated version of the CORD-10 dataset, which is a collection of COVID-19 related scientific papers and their embeddings (based on title + abstract and the allenai/specter language model)
  • For every new (i.e. unseen) query, I embed it, and I first consult simple cosine similarity to get a top-5 list of matching documents. I (pairwisely) train a model on this result set on 100 epochs.
  • Let a query's result set be an ordered list of documents (1,2,3,4,5). If a user now selects result 3, we loosely (10 epochs) train the existing model on the desired order (3,1,2,4,5).

Demo
Kapture 2023-06-02 at 13 21 39

Code

Remarks

  • A query's result set is eternally biased and restricted to the top-5 results returned by the initial document matching -> Remedy idea: some measure of exploitation/exploration balancing.
  • A single model will be trained on multiple queries. I haven't thought through the dynamics this would have, if they are useful or disruptive or how they can be exploited.

@synctext
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synctext commented Jun 6, 2023

Sprint: get a solid production-level metadata dataset (Creative Commons, https://github.com/MTG/mtg-jamendo-dataset ?)

@mg98
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mg98 commented Jun 11, 2023

Update:
I have started giving more time again to my first thesis chapter (the one I started writing several months ago, with a colleague). Work title: "A Comprehensive Study of Content-Defined Chunking Algorithms for Data Deduplication". I want tot finish this within the next 1-2 months!

MeritRank+crowdsourcing phd chapter 2023?
Learn-to-rank 2024 thesis chapter?

Love this roadmap!! ❤️

I have started getting my hands on the Tribler code and gain a better understanding of its inner workings. Will try to move forward with the practical preparatory work for the next thesis chapter, such as getting a dataset.

@mg98
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mg98 commented Jul 12, 2023

Over the last month, I was mainly focused on my first thesis chapter. That involved writing, but also running experiments, fixing bugs in our code, and figuring out the best way to present our data.

For example, visualising the chunk size distribution was a challenge because of the amount of experiments and amount of algorithms we evaluate. Furthermore, the variance in behavior made it difficult to fit everything into a single plot while preserving readability.

Apart from this, I was reading some papers, talking to my peers in the lab, trying to understand what they're doing, and also continuing to explore AI/ML, e.g., learning about transformers.

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synctext commented Jul 12, 2023

Please write 3 next paper ideas around topic of "Web3 crowdsourcing". 6-page for DICG 4th workshop would be indeed a great learning. One of 3: crowdsourcing of metadata using MeritRank; everybody can tag, describe work done of KnowledgeGraph, desing an Algorithm 1, discover tags, rate them using MeritRank, emulation using Bulat Python magic, epic Sybil attack. take Rohan algorithm, get going in tag context instead of recommendation, improve somewhat.

Great news, hoping chapter to be ready for final reading & submission aug/sep. As a starting point for new lab people a short history and essential reading.

Year Topic Milestone description
2000 vision Open Information Pools was the first paper with the dream of establishing a new Internet. Now grown into the Web3 movement. Dreams of a young man, taking 23 years to realise and still counting. A reputation function calculates a reputation based on several aspects of the user, like the amount of activity of the user, number of retrievals of his submitted information, the number of modi�cations to his submissions, etc.
2006 vision Tribler, initial overview. First deployment of social networking with academically pure self-organisation
2008 vision we reported on BarterCast feedback loop
2023 vision A Deployment-First Methodology to Mechanism Design and Refinement in Distributed Systems
2020 trust TrustChain: A Sybil-resistant scalable blockchain
2018 trust trustchain IETF draft Internet standard https://www.ietf.org/archive/id/draft-pouwelse-trustchain-01.txt
2018 trust we formulated the improved feedback loop
2019 trust Jeremie is now a professor at Delft: RepuCoin: Your Reputation is Your Power
2021 trust Foundations of Peer-to-Peer Reputation
2023 trust Meritrank solves the impossibility result formulated by Prof Parkes of Harvard. A reputation system which might actually induce online trust.
2010 community Private communities help eachother, biggest measurement ever conducted. No tit-for-tat in most of the time with private communities, see Figure 6. image
2011 community competition due to oversupply. Fast download but eternal seeding: The reward and punishment of Sharing Ratio Enforcement
2013 community Systemic Risk and User-Level Performance in Private P2P Communities
2020 DAO Technology Stack for Decentralized Mobile Services (Matt Scala)
2021 DAO Towards a Robot Economy for the Music Industry (Tim Wissel)
2022 DAO Web3: A Decentralized Societal Infrastructure for Identity, Trust, Money, and Data (Joost Bambacht)
2023 DAO Performance analysis of an offline digital Euro prototype (Robbert Koning)
2023 DAO First Deployed DAO with True Full Decentralisation (Brian Planje)
2023 AI MoDeST: Bridging the Gap between Federated and Decentralized Learning with Decentralized Sampling
2023 AI Decentralised recommendations with trust and relevance (Rohan)
2023 AI Towards Sybil Resilience in Decentralized Learning (Thomas)

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New ACM Journal on Collective Intelligence seems like a solid venue to target. Your second chapter could then simply be decentralised collective intelligence. Using Tribler to share info, use tagging, and trust. You can re-publish a lot of the Tribler work done by others in the past 18 years and 3 months.
the journal encourages a broad-minded approach to collective performance. We welcome perspectives that emphasize traditional views of intelligence as well as optimality, satisficing, robustness, adaptability, and wisdom. In more technical terms, this includes issues related to collective output quality and assessment, aggregation of information and related topics (e.g., network structure and dynamics, higher-order vs. pairwise interactions, spatial and temporal synchronization, diversity, etc.), accumulation of information by individuals/components, environmental complexity, evolutionary considerations, and design of systems and platforms fostering collective intelligence.

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@mg98
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mg98 commented Aug 6, 2023

To give a little update...

  • I skim-read through the complete list of papers and made my notes for each one.
  • My thesis chapter has seen great progress but is currently blocked again by my co-author who is on vacation now.
  • I have consulted with Bulat about your proposed paper idea (DICG) to understand and plan the required steps. I have yet to get a better understanding of the field to come up with my own ideas for topics.

@mg98
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mg98 commented Aug 14, 2023

I'm focusing on the DICG'23 now. @grimadas

MovieLens Dataset

I was able to find a really nice dataset. MovieLens is a non-commercial project run by people from U. Minnesota since 1995. It's a database of movies that users are allowed to rate and tag. Any user can add new tags, and existing tags can be up- and downvoted in a way (see screenshot).

Screenshot 2023-08-14 at 19 09 21

Tags also have the attribute of being positive, neutral, or negative. I am not sure how complete their dataset is about that, but they are responsive to my emails and seem highly cooperative with the provision of data.

We can use this dataset to get an idea of the quantity and quality when it comes to crowdsourcing of tags, and base our simulations on it.

Quick plots...
Screenshot 2023-08-09 at 18 04 42Screenshot 2023-08-14 at 20 30 26

Idea

Perhaps, for this workshop, I could come up with some subjective tag scoring algorithm, a bit related to the "Justin Bieber is gay" problem. Playing with the idea that for a group of similar users, a tag might be agreed upon, but for another group of users the same might not, etc.
Regarding the beforementioned question, there might be a community of users (with similar taste) for whom he is, and another community for whom he isn't. Therefore, introducing the notion of "subjective reality".
What indicates user affinity? It could be that they are interested in similar content, i.e., they interacted (tagged or rated) with similar movies.

Approach

  • Propose some algorithm that for a tuple (peer, resource, tag) can calculate a score in [0,1].
  • Introduce the notion of user affinity by some metric of has-interacted-with-similar-movies.
  • Make plots and observations... Perhaps we can visualize the 'bubbles' of communities that are created by this metric of user affinity and how they support different tags. It will depend on the quality of the dataset though, I'm yet skeptical.
  • Simulate my subjective tag scoring algorithm and observe its effects. Given the tags that the user has agreed and disagreed on in the dataset, we could be able to introduce a metric of success for this algorithm. My concern here again is potentially the lack of data. We rely on the existence of a big enough set of highly active users whose contributions are distributed on not too many movies.

Will further investigate this idea and the dataset and make updates here. Comments welcome.

@devos50
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devos50 commented Aug 15, 2023

Just noticed this line of work, very interesting! I worked on something similar (trust, tags + MovieLens dataset) more than a year ago, see this issue (note that this is a private repo with many of our research ideas so you might have to request access). The overall goal of that issue was to work on the foundation of tag-centric crowdsourcing in Tribler.

I tried out a few algorithms/approaches and I remember I identified some shortcomings of Credence, which is related to what you're trying to achieve. but as reputation/trust was not really my domain, I decided to focus on the fundamental data structures instead (using Skip Graphs and Knowledge Graphs for Web3 data management). The paper with these ideas is currently under review. Nonetheless, extending that work with a trust layer would be a valuable contribution!

@mg98
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mg98 commented Aug 28, 2023

Hi Martijn :) thanks for your input!

I was knocked out by COVID over the last two weeks, and still am a bit, but here is the continuation of what I was trying to do:

I have calculated user similarity based on the Pearson correlation of common sets of rated movies (as suggested here), and based on that, subjective tags on movies (indeed similar to Credence in that I weigh based on peer correlation). I based this solely on the interactions of the 200 most active users (perf reasons).

Example of a sample of users and their subjective tags on the movie "The Shawshank Redemption"
              tag     score
126      friendship  1.465223
260          prison  1.367187
8    Morgan Freeman  0.966742
275            rape  0.924138
151            hope  0.854776
          tag     score
126  friendship  1.109590
260      prison  1.103990
275        rape  0.703847
151        hope  0.673232
285  redemption  0.673232
            tag     score
247        prison  1.158236
121    friendship  0.947820
293       revenge  0.735881
333       suicide  0.685857
134  great ending  0.578089

From there on, I tried to find extreme results, i.e., movie tags for users of "opposite" groups. To this end, I looked up controversial movies and their tags for users with minimum/negative correlation, hoping for something like a clear political or a gender split.

And it wasn't easy, perhaps due to the lack of data. But I still found an interesting disparity for Disney's Star Wars remake.

While one user has funny, good action, and great action among his top tags,
another user has Bad jokes, Weird Pacing, boring long, and Script Recycle among its top tags, and further, feminism and social justice.
Most of these tags exist with negative scores in the list of tags of the respective other user.

Full list of tags for two negatively correlated users on "Star Wars: The Last Jedi"
                 tag     score
29         plot twists  0.181055
4     Benicio del Toro  0.181055
1                 BB-8  0.181055
16         Space opera  0.181055
7                Funny  0.181055
8          Good Action  0.181055
9     Gorgeous visuals  0.181055
10        Great action  0.181055
12       John Williams  0.181055
17           Star Wars  0.126848
13         Mark Hamill  0.126848
18  Strong female lead  0.126848
14        Rian Johnson  0.126848
0          Adam Driver  0.099062
6         Daisy Ridley  0.099062
3    Bechdel Test:Pass  0.048224
19        Weird Pacing  0.048224
20              boring  0.048224
34        stormtrooper  0.036496
28     part of trilogy  0.036496
33         space opera  0.036496
21              bunker  0.036496
22              defeat  0.036496
23             failure  0.036496
32        space battle  0.036496
25        good vs evil  0.036496
30              sequel  0.036496
27  military operation  0.036496
24            feminism  0.020438
31      social justice -0.027786
2            Bad jokes -0.033770
15      Script Recycle -0.054207
5        Carrie Fisher -0.054207
11         John Boyega -0.054207
26                long -0.170404
                  tag     score
1            Bad jokes  0.854447
16            feminism  0.730180
0          Adam Driver  0.440624
4         Daisy Ridley  0.440624
2    Bechdel Test:Pass  0.413822
11        Weird Pacing  0.413822
12              boring  0.413822
15             failure  0.410806
24         space opera  0.410806
23        space battle  0.410806
21              sequel  0.410806
20     part of trilogy  0.410806
19  military operation  0.410806
17        good vs evil  0.410806
13              bunker  0.410806
14              defeat  0.410806
25        stormtrooper  0.410806
22      social justice  0.316358
10  Strong female lead  0.124267
9            Star Wars  0.124267
8       Script Recycle  0.124267
7         Rian Johnson  0.124267
6          Mark Hamill  0.124267
5          John Boyega  0.124267
3        Carrie Fisher  0.124267
18                long  0.101508 

That was fun to explore but it still lacks a scientific methodology in order to really evaluate the effectiveness of the subjective tags I computed. Previously, I proposed that

Given the tags that the user has agreed and disagreed on in the dataset, we could be able to introduce a metric of success for this algorithm.

Maybe that gives us something. Maybe for all tags that have been up- and down-voted, I can compare the subjective with the objective reality and derive a success metric. And this would allow me to experiment with more sophisticated scoring algorithms and see their effect on this metric.

The paper with these ideas is currently under review. Nonetheless, extending that work with a trust layer would be a valuable contribution!

Good stuff. I don't know if trust should be my scope either. I'll talk to Johan today, will know more then.


Status update on

Please write 3 next paper ideas around topic of "Web3 crowdsourcing".

After almost half a year, I still don't have a grasp of the field enough to come up with own ideas for publications.

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synctext commented Aug 29, 2023

No worries about your progress in 6 months of a 48 months phd. Getting into the field of distributed system and doing something novel is hard. Having a draft publication within the first 12 months is already a solid achievement. Goal: April 2024 == 1 thesis chapter under review + 1 finished draft thesis chapter. Non-linear productivity 📈

Task for September 2023: come up with ideas for a scientific paper and select one (or get inspiration)

SwarmLLM: collective LLM intelligence (with new AI phd expert??)

We present the first proof-of-principle of collective intelligence for transformers. Intelligence emerges from the interaction between numerous elements [REFS]. We use a transformer as the basic building block for a interconnected network of connected unique transformers. Instead of the classical transformer approach with billions of parameters, we connect thousands of specialised transformers into a network. This is a generalisation of the mixture of experts approach with the highly desired new property of unbounded scalability. There is a cost to pay in our approach. In a typical divide and conquer style, the challenge of finding the correct expert becomes harder.
Go beyond deepswarm, a system with outdated MNIST evaluation from 2019 using pheromone update rules.

LLM as a key/value store

key: any youtube URL in Youtube-8M dataset.
value: the preview thumbnail generated {re-usage of your autoencoder idea??!!}
With sharding and multiple LLMs per node a unique datase can be spread in a ring topology, ordered by the keyspace.
Semantic clustering or not?

Rich metadata inside an LLM

Tulip picture embedding in generic form.
Rich metadata embedding of "artist passport" Cullah.
Cullah donation wallet 1FfnfPJJ6yTTT9PGZe8TGgfEGQFc9kvQoW
Linkage with strong identity and GoldEuro direct donation by superfans.

Tribler: a public semantic search engine

We shamelessly claim to have a proof-of-principle for public Internet infrastructure after 20 years of effort. We argue that critical societal infrastructure should be developed as a non-profit endeavour. Similar to Bittorrent and Bitcoin we present a self-organising system for semantic search. Our work is based on learn-to-rank and clicklog gossip with privacy-enhancing technology using a Tor-derived protocol.

Web3Search: Online Pairwise Learning to Rank by Divide-and-Conquer with full decentralisation

Embedding nodes using algorithms like node2vec. Embedding of any item using 50-ish dimensional vector.
Fully decentralise and make trustworthy, this older work from 2021: https://arxiv.org/abs/2103.00368
Dataset: Covid papers, Youtube-8M, creative commons magnet scrapes??

Foundations of Trust and Tags.

Use the @grimadas work with theoretical grounding: emergence of trust networks with repeated successful interactions. Use tags based on crowdsourcing if you have successfully collaborated.
"The extended mind", classic reading from 1998.

Next steps: learn-by-doing methodology. Work for 2 weeks further on the Tulip stuff. Autoencoder of 1000-ish Youtube-8M thumbnails. Work for 2 weeks on another of above brainfarts. Commit to best chapter idea.

@mg98
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mg98 commented Aug 31, 2023

Seeing how far I can get autoencoding YouTube thumbnails. Time for some quick coding.

Using YouTube's API I got the thumbnails of 577 search results with "starship" as the query.
I'm using the same network parameters as I used for the tulips but with fewer input neurons (the thumbnails are 4x smaller in size).
However, it's not like YouTube thumbnails are good representations of the queried terms, nor is there necessarily a high similarity of visual features throughout the thumbnails in the search results, as you can easily verify: https://www.youtube.com/results?search_query=starship, or browse the YT 8M Dataset Explorer.

Note

Using YouTube's search API instead of its 8M dataset (can't run that on my machine!) is different in that I collect the thumbnails of videos which match the search query, and in the 8M dataset they sort of match the query (selected set of visual entities) with what they actually found displayed in the video.

I still went with it, trained the network on 576 thumbnails, and then ran the 577th search result's thumbnail through the autoencoder.
InputInput

Initially confused about how well that went... Because, as I implied, I don't think the fed set of images works much better than any arbitrary collection of images. It's funny though because technically it's a data reduction from 32K worth of information down to 4K (the size of the model), and 4K is also exactly what JPEG compression gets for the original image. So I probably just built myself a generic image compressor. (error, see my next comment)

What might do is the labeling we get on frame-level (or ~1-second-interval video segments). We have that in the 8M dataset. Getting an actual image entails downloading the original YouTube video and then extracting the corresponding frame. That's costly but doable on a small to mid scale.


We have been thinking about doing text-to-image basically, using auto-encoders? I think that was the plan...
The 8M dataset contains embeddings on video segments/frames. It would be cool to be able to embed a custom query like "starship" and then find video segments near it. But it doesn't work that easily. The 8M model is not trained on text. We only get fixed labels, e.g., we have "guitar", "toy", "minecraft", a few thousands of those. "starship" is not part of this taxonomy. Perhaps we can use a separate model to link semantics between "starship" and the labels in the 8M dataset and thereby make our way...
Tbc

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wow, as impressive as I hoped it would be!! 4k!
Just drop the YouTube 8M for now and focus on the 1000 Starship thumbnails. How good can you autoencode them all?
What tradeoffs? What does 5 days of M2 GPU crunching yields?

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mg98 commented Aug 31, 2023

There was an error in my code, and a bit in the approach. What I did was training only on 50 thumbnails, and then use a thumbnail that was part of the training data for testing. I updated my last comment; the result is very different.

Click here to see previous (misleading) result

InputInput

What does 5 days of M2 GPU crunching yields?

Actually, PyTorch does not support CUDA (GPU acceleration) on Mac :( Google Colab with GPU runs faster for me.

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mg98 commented Oct 17, 2023

Quick update:

  • Without the metadata overhead created by PyTorch, we can compress the model to 0.72 MB instead of 2.7 MB
  • Using quantization, as suggested by the MIT guys, we can cut it down to a quarter (i.e., 0.18 MB)
  • We still have not made efforts to optimize our hyperparameters. Perhaps we can do with fewer neurons, fewer layers.

Sparse weight updates seem like a good idea. See our following experiment:

Training alters only a subset of parameters (30-80% and possibly less)
(base) ➜  p2p-ol2r git:(main) ✗ python main.py 1
Indexing (please wait)...
QUERY: molecular tumor
Epoch [10/10], Loss: 0.4321
593859/721921 parameters changed (82%)
QUERY: molecular tumor
Epoch [10/10], Loss: 0.2447
498198/721921 parameters changed (69%)
QUERY: molecular tumor
Epoch [10/10], Loss: 0.0749
368436/721921 parameters changed (51%)
QUERY: molecular tumor
Epoch [10/10], Loss: 0.3645
427678/721921 parameters changed (59%)
QUERY: corona
Epoch [10/10], Loss: 0.2711
426012/721921 parameters changed (59%)
QUERY: corona
Epoch [10/10], Loss: 0.4429
311566/721921 parameters changed (43%)
QUERY: corona
Epoch [10/10], Loss: 0.1320
258525/721921 parameters changed (35%)
QUERY: corona
Epoch [10/10], Loss: 0.1076
218907/721921 parameters changed (30%)
QUERY: corona
Epoch [10/10], Loss: 0.4273
226130/721921 parameters changed (31%)
QUERY: cancer
Epoch [10/10], Loss: 0.2630
498395/721921 parameters changed (69%)
QUERY: cancer
Epoch [10/10], Loss: 0.3669
394564/721921 parameters changed (54%)

However, those require proper annotation which would blow up the size. I doubt it's worth pruning only the 0-delta params.
I wonder, though, can we set a threshold on weight deltas before propagation? Is the intuition right that major weight deltas contribute to the model output more than minor weight deltas (or the combination of many minor weight deltas)?
Looking at quantization (essentially rounding params ooh it's more than that), it seems like it is!
Still, I haven't found a gossip learning paper talking about this yet.

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synctext commented Oct 20, 2023

ToDo: Determine an effective deployment plan. Grand idea: quick to production and iterate fast - ELON style.

  • 0️⃣ First data phase. Create Youtube/Bittorrent swarm dataset in maximum 3 days. Focus on getting started, training, and simple ML code.
  • 🚫 NO ML phase. read-only community of the tripplets. You get them only if you specifically ask for them. Crawl. Check validity. (7.14)
  • ✅ Offline ML phase . Use the production network to test Tribler version which collects these tripplets. Use the production network to train your offline AI weights.
  • ✔️ Simple ML phase, on-device AI architecture. Add a few semantic results inside the traditional syntax-matching search pipeline. Avoid the cold start problem by giving hard-coded starting weights inside the Tribler 7.15 release. Triplets are exchanged and used to further train the model locally.
  • ☑️ Improved gossip learning. All search results come from machine learning. We have a lot of training data from production now (both 7.14 and 7.15). This is used to tune, tweak and re-work the model for faster training, efficiency, and effectiveness in general. Use tags as key source of model intelligence? Full usage of metadata enrichment and crowdsourcing.

Reason for pushing strong on simple gossip exchange of human readable data versus model exchange with pure magic numbers. stability, ease of debugging, correctness, convergence, expertise of team, bloat in ML libraries, and lack of machine learning maturity. Really everything is in favour of doing gossip learning with data exchange, only true AI expert would do maximal AI. Easy low hanging fruit for a scientific in-depth 2nd paper: Distributed artificial intelligence: empirical proof for the model exchange versus data exchange paradigm (thesis chapter @pneague or @mg98). silly idea: learning aggragation and compression. Locality of learning to guard horizontal scalability, instead of global broadcast of 1 day of node-learning.

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mg98 commented Oct 22, 2023

Update on my experiments with Quantization

It's not as trivial as I thought, and I'm not sure if I fully understood it, but I'll try to give an explanation for those interested:

Quantization: Introduction & Overview

Quantization is a technique that is used to shrink a model's size by basically discretizing its parameters. This makes computations on the model faster and more memory-efficient. Typically, weights and activations are quantized from float32 to int8 following the formula $\lfloor w \cdot (2^{b-1}-1) \rceil$, where $b$ indicates the precision (roughly speaking).

Quantization relies on a phase of calibration in which it learns the typical range (scale) and zero-point of individual tensors, thereby optimizing the quantization parameters.

There exist three ways to do quantization.
Screenshot 2023-10-22 at 12 36 00

We are interested in Quantization-Aware Training. In this mode, there is no separate calibration stage (which wouldn't work in our use case). Instead, the model is in a quantization-prepared mode, constantly fine-tuning its parameters, but never actually quantized until conversion.
We get great computational overhead... but we still end up with a quarter of the file size when transmitting it over the network 💪🏻 which is our main objective 🎯

If you are interested in learning more, I found this source the easiest to follow. However, I think the full process behind PyTorch's quantization is more sophisticated and, frankly, still a little mysterious to me.

It also took me a while to implement it. Aggregating a quantized model with an unquantized-but-prepared-to-quantize model is, again, not a trivial task.

In the end, I got it to work. Below I show a demo without and then with quantization. (By the way, the UI evolved ☺️)

Demo.mp4
Demo.Quantization.mp4

Observations:

  • 🥲 Training and inference got much slower
  • 🎯 Transmitting the entire model in 92 instead of 354 packets (of 8 KB). We could easily get it further down (in the order of magnitude) by stripping the metadata off.
  • 😭 The loss in accuracy is extreme, and perhaps unacceptable. Furthermore, I was not able to improve it by tweaking the hyperparameters or number of epochs. So that's a problem!

I think I'll pause it at this point, and switch my focus to the dataset, maybe do some empirical analysis.

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mg98 commented Nov 7, 2023

I discovered that our ranking model does not perform nearly as well as I thought. Reasons being a small set of results (length 5), which inherently resulted in minor ranking errors, as well as my own confirmation bias which gave undue credit to the occasional successes. Above all, our testing lacked a rigorous analytical approach.

Thus, the last two weeks have been an intense period of debugging, refactoring, and testing.

I increased the number of results to around 10 and introduced an evaluation metric (nDCG) to gauge the model's performance--it was about random😑. This led me to experiment with new loss functions, new optimizers, even new model designs, in addition to all the other hyperparameters like model size, epochs, learning rate, ... I learned that those little things can often have a dramatic impact on the performance. Furthermore, I learned about overfitting and dropout regularization.

I made everything configurable! And played around with the options running against my automated tests. Tweaking around, I managed to get near-optimal performance with 10 results (according to my simulation of 5,500 user signals).

To further optimize my parameters, I plan to adopt a systematic approach to parameter search. I know that there exist some tools (e.g., RayTune) that can do this intelligently... will read into that... in any case, being able to control everything from my config.ini lays a solid foundation to do that, even on my own.

Another major concern that arose was the effect of the number of epochs on the model accuracy. In an online (= continuous learning) environment, the number of epochs is not only arbitrary but also ever-increasing. Therefore, with static parameters the model will always continue to overfit. We'll have to dig the OL2R papers to see how they dealt with it... My guess is the solution will involve something like adaptive learning rates.

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mg98 commented Nov 27, 2023

On a hybrid work/vacation until mid-December. Trying to recap and orient myself in my research:

Broader Goal: Better information retrieval in decentralized systems

Explored Methods:

  • Mainly LTR
  • Recently started reading into LLM for IR (what Petru's digging atm)
  • (Metadata.... the important other half when doing IR. Haven't got anywhere with it yet. Listing for completeness.)

Roadmap:

  • I want to continue working on a functional prototype for Decentralized LTR (repo)
  • Focus could be
    • the comparison of data exchange models (gossiping training data vs. model weights).
    • Personalization is another interesting domain to investigate, but that might be for later
  • In need of a dataset to evaluate my model's performance. Concretely, I need a dataset that provides me
    • search queries
    • static list of top-k results given query
    • which document has been clicked
    • document vectors
  • Often, the list of relevant results is what is missing from available datasets. Collecting data from Tribler?

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mg98 commented Dec 22, 2023

Continual learning

Quick-fix for the overfitting problem of continuous LTR (= indefinitely growing number of epochs). I applied an exp learning rate decay and found parameters which converge to optimal ranking.

How I think LTR relates to the DSI approach

The DSI approach is capable of retrieve-and-rank. And I'm trying to understand where this leaves traditional LTR. My idea is that LTR's power lies in the consideration of user signals (click-through rates in particular) which go beyond semantic relationships, primarily, and then the potential for personalization, secondly. In which case LTR could complement this model in a two-stage IR system where the second stage is concerned with the reranking of the previously retrieved result set.

Another thought:

LTR comes in where metadata is insufficient. You could have great content, and shitty content, both with equal metadata. Scientific problem: Spam, clickbait, and the hidden gems are indistinguishable for most algorithms. On personalization: One person's gem is another man's clickbait.

In a future work, it would be interesting to test this out in a first-DSI-then-LTR architecture and evaluate if and how far LTR's re-ranking capabilities change the ranking of search results, and finally improve the accuracy of search results. The latter could be measured by metrics like clicks @ 1st result, for example. Empiric dataset required.

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synctext commented Dec 22, 2023

Possible next paper: DSI-then-LTR two-stage IR system. Another key issue for real-world usability is the bundeling and filtering of near-duplicate items as we started to experiment with in 2022:

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synctext commented Jan 8, 2024

  • ongoing work on the "A Comprehensive Study of Content-Defined Chunking for Data Deduplication" paper. With 27-pages it's complete, but text polishing remains. Hard to compete with chunks against bleeding edge sexy ML. (March target (acm transactions on storage???, solid thesis chapter)
  • DSI-then-LTR two-stage IR system finish on 19 Jan!
  • brainstorm on next-next paper
    • crowdsourcing direction
    • end-to-end LLM for Tribler/Netflix

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mg98 commented Jan 23, 2024

  • Still working on the completion of my thesis chapter
  • Still working with Petru on Decentralized DSI paper (target EuroMLSys with deadline on 20th Feb)
  • Btw, we can finally use DAS6! 🚀 very much needed
  • Brainstorming other ideas, like...

Queries Is All You Need

When Google presented DSI, they had the luxury of knowing complete document texts. These were used as the foundation in training their LLM to map queries to (arbitrary) docids. They further state:

[...] it is clear that examples of type [query->docid] alone do not provide enough information for a system to generalize to novel retrievals [...]

Petru, lacking any document contents or metadata, trained solely on query-docid pairs. Astoninglishly, this model became able to output the correct docid to unseen queries (i.e., generalize to new inputs).

This is a discovery that deserves more attention for its implications in search, especially in systems where metadata is scarce.

Can we really describe documents by (and solely by) the queries people used to find it? Can we maybe by collecting enough diverse queries to a popular document, have a model learn the document's rich semantic profile?

Those, I think, are ideas worth an examination in another short-formed paper.

</Pitch>

Time for a first figure. I designed a simple experiment using a small subset of the ORCAS dataset.

  • I'm using T5-small as a base model (60 million parameters).
  • I took a sample of 100 documents with samples of 200 associated (ambiguous) queries, respectively (i.e., 100x200=20000 query-docid pairs)
  • For n=1..10, I reduced this dataset such that it's 100 documents with only n associated queries, respectively. This would become my train dataset. My test dataset would be what is left from the initial dataset.
  • After each iteration, the model is reset.
  • I trained on this dataset on 650-n*30 epochs. This is a formula that aimed to train the dataset with 100% accuracy, without over-training it (i.e., accuracies are 96%+)
  • From the test dataset, I took a sample of 100 queries for each document (i.e., 100x100=10000 query-docid pairs with unseen queries), and measured the model's accuracy on them.
  • Experiments conducted on a single node in DAS6, takes about a day to run with this setup. Parallelization on multiple nodes possible, though.

Experiment setup might have some flaws, but I hope with my first figure to give a general idea, which should be: the majority of queries can be processed successfully given only very few (according to experiment at least 2) prior queries to the sought document.

(y = success rate on unseen queries)

I wanna try again with 1000 (instead of 100) of distinct documents. Will update here.

Live update: (1, 10%), (2, 23%), (3, 27%), (4, 32%), ... so it definitely has the capacity to decrease sharply as the output space grows, but still fair results

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synctext commented Jan 30, 2024

  • Great results!!
  • It seems likely you can write a paper with the 'queries is all you need' idea
  • Lets not work on 3 papers at the same time. Submit something before diving further.
  • It covers 1.4 million of the TREC DL documents, providing 18 million connections to 10 million distinct queries. One ORCAS use case is Web mining, to find clusters of related queries and/or related documents. These can be mined for synonyms, used for expanding and understanding the vocabulary of queries and documents. The 10 million queries could be used in studies of query autocompletion., from https://microsoft.github.io/msmarco/ORCAS.html
  • Expand that golden figure! Start writing the first experimentation section; 1-2 pages. No intro, No problem, no related work.
  • Exaggerate! Artificially pick the most extreme example which produces the best results. Select from the 10 million queries the most clustered ones? Select the document with the most ambiguous queries? Select the documents with the most similar queries?
  • Storyline idea: In this experimental section we first present our motivation example and then elaborate with detailed performance analysis. The first experiment is chosen specifically for simplicity and dramatic effectiveness.
  • 1 thesis chapter on block storage, 1 thesis chapter on 'queries all you need'
    • Active learning (crowdsourcing, knowledge graph)?
    • Continuous learning?

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mg98 commented Mar 7, 2024

It's time for another update. I have been conducting more and more experiments, as I was trying to better understand what's going on.

Here is one very interesting finding:

💡 More popular documents have a more diverse semantic range of queries than more niche documents.

⚠️ Caveat: "More popular" just means those document have a larger number of distinct associated queries.

For example, people who looked for Gmail got successful querying "google login online" but also "create a new account".

We can also visualize that by clustering the embeddings for queries of low popularity (40-50 queries), and queries of high popularity (1000+ queries) on a 2D semantic space. (Dots represent queries, color-coded by their associated document)

download-3

As we can see, the queries of popular documents are semantically more dispersed, which makes them more difficult to group them together just by looking at their position. In other words, if you let k-means do the clustering (intuitively what our model would do), the mismatch rate would be higher with the high-pop docs than with the low-pop docs.

There are also metrics to quantify that. In the following figure, I have plotted the Adjusted Rand Index (ARI) of the clustering and increasing document popularity.

ARI values range from -1 to 1. A score of 1 indicates a perfect match between the clustering results and the ground truth, while a score of 0 indicates random clustering, and a negative score suggests less agreement than expected by chance.

I have plotted this for 20 docs and for 40 docs, to show that of course the more documents share the same semantic space, the more crowded the queries get, and the more unreliable the clustering.

Finally, this is of course reflected in the accuracy the model can attain, as shows the following example (here with 100 docs trained on 10 queries).


💡 Second finding is that the model often hallucinates, and beam search sometimes duplicates results.

I call a result a hallucination (or invalid) if it outputs a string that was not part of the outputs it got trained on.

This means that if you have a system where you are aware of the existing documents, you can instead take the first valid docid output by beam search, and therefore bump the accuracy.

On the lowest range of our experiments (100 docs and 1 query fed) this made a difference of +3%. However, on the upper end it is rather negligible. The following shows an excerpt of the results.

Documents Queries acc@top1valid acc@top1 acc@top3 acc@top5 inv@top1 inv@top3 inv@top5 dup@top5
100 1 0.4265 0.3955 0.457 0.483 0.2185 0.534833 0.6417 0.0006
100 5 0.824 0.8235 0.898 0.9365 0.0015 0.2255 0.307 0.0185
100 10 0.878 0.8775 1 1 0.002 0.227833 0.3431 0.1753
100 20 0.932 0.932 1 1 0.0015 0.327833 0.4391 0.0628
1000 1 0.20515 0.157 0.198 0.2156 0.58495 0.757117 0.81045 0
1000 5 0.68995 0.68925 0.77 0.80935 0.006 0.16825 0.23343 0.01082
1000 10 0.79405 0.79385 0.96025 1 0.0014 0.191117 0.2658 0.07091
1000 20 0.832 0.8314 0.93815 1 0.0022 0.217933 0.28892 0.04126

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mg98 commented Apr 8, 2024

I have been digging into some papers in the context of the upcoming Queries-Is-All-You-Need chapter and potential future work. Dumping my learnings here.

Neural Corpus Indexer (NCI) [PDF]

Abstract: NCI is currently probably the best-performing version of DSI (after GenRet 😉 see below). NCI and others, however, gain most of their extra performance from leveraging document contents.

Most of these proposed systems, like also DSI-QG and SEAL, leverage knowledge over the document contents. For example, they will artificially generate queries to train on, or create semantic docids based on the contents (e.g., SEAL does ngrams for indices/docids).
So it's important to keep those technologies out of scope - we are interested in content-oblivious search.
NCI is interesting because they--besides doing a lot of other things--offer two technological improvements that do not rely on document knowledge:

  • Prefix-aware weight-adaptive (PAWA) decoder
  • Consistency-based regularization

Combined, these changes increased the Recall@1 from 62.57 to 65.86.

DSI++ [PDF]

Abstract: This is an update by the original authors of DSI to equip DSI with eternal learning (aka continuous or lifelong learning).

This is how they do it:

  • They optimize for flatter loss basins. There's this thing called Sharpness Aware Minimization (SAM), which seeks out flatter areas within the loss landscape. My intuition around this is that you have a wider area of tolerance when new things are learned and altered parameters shift the loss.
  • Then, they employ a second model (generative memory) that keeps generating pseudo-queries for previously learned stuff. This is then fed into the DSI for rehearsal.

GenRet [PDF]

Abstract: Using an autoencoder to learn to tokenize documents (my idea is to use the mean of the collection of associated queries instead) into short semantic docids.

The accuracy drops as soon as you replace ORCAS' docids D1234839 to magnet links 0xabcde...40 chars. Intuitively, the more tokens the model needs to generate, the more likely it will make a "typo".
Therefore, I asked myself how can we represent N documents using the least number of tokens. I naively tried to create docids myself where I calculated the shortest length of characters or tokens with which I could still create N unique combinations. But turns out, it either performs worse or equal to ORCAS docids. It apparently is not that simple because of the semantic meaning that is carried with every token.

So instead of writing a docid tokenization function myself, I would like to learn a function that does the docid tokenization. This is what the authors of GenRet did, and thereby (and only thereby) outperformed NCI (which got most of its performance from extracting document knowledge -- we could maybe do GenRet's technique using queries only).

I roughly understood the theory of how they were doing it, but luckily they are also open source (repo), I will try to get it to work and run experiments.


Other Interesting Papers for Future Work

  • DynamicRetriever team combined DSI with actual Learn-to-Rank [PDF]
  • Same team was also working on personalized LLM-retrieval, idk how it works [PDF]
  • DSI team published TIGER: Recommender system using LLM with I/O of form (doc1, doc2, doc3) -> (doc4) [PDF]

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synctext commented Apr 10, 2024

update : (more paper ideas then finished chapter, simply documenting)
A Survey of Hallucination in Large Foundation Models. Would it be possible to filter hallucination of our magnet link generative AI (Queries Is All You Need)? The popularity community is a gossip mechanism to update statistics of millions of torrents. We should be able to track dead torrents, popular torrents, and hallucination torrents.

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mg98 commented Apr 12, 2024

"learn to tokenize documents"

I got the script to work (GenRet). However, I was rethinking this idea and I don't see how we could sell it. Learning semantic docids from the queries themselves obviously requires you to have the queries beforehand, and even then it implies some fluidity (cannot just "improve" the ID in the continuum).
If anything, DSI's hierarchical clustering is much better suited for semantic docids, because here at least the semantic space on which it clusters it is fixed. GenRet really goes one step further and limits the space to what the document space encompasses. [my understanding]

I'm dropping this!

roadmap on life-long decentralised learning [...] what is the first realistic next step?

Yeah as you listed: overfitting, pollution, spam, those are also things that come to my mind. While there are some ideas how it could work conceptually (e.g., DSI++, IncDSI), the datasets they use to validate them are a bit weak (in those papers, NQ and MS MARCO). For a real evaluation, we (1) need real search queries, including spam, but also (2) we should care about the chronological order that the queries come in, and that the model learns on.

Waiting for the Tribler Clicklog.

Would it be possible to filter hallucination of our magnet link generative AI (Queries Is All You Need)?

Not in the way that is described in this body of research (referring to your survey link), I think.
What I have already done in my experiments is to restrict the vocabulary of the generator and control the length. This way you can tune it a little bit to the pattern of a docid.

What we can do in the next step is to assume knowledge of, let's say, healthy torrents. Using this knowledge, the model will be configured to predict the most likely token, with which the resulting output continues to match a prefix found within the set of healthy torrents.

Will do!

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mg98 commented May 7, 2024

Representation of Targets Matter

In our last paper, we saw significant differences in performance when representing our targets as ORCAS docids (e.g., D1234567) vs. as magnet links (40 character hex string). The model would generally have a harder time predicting magnet links. We blamed this on their length; more tokens to generate, more chances to trip along the way.

When thinking about how to optimize the performance of our model, I therefore thought the number of tokens on a docid should be minimized. Why not use the entire ASCII space for example? Or hell, the T5-small has 32k tokens, why not encode docids as, for instance, "car 2001": two tokens, 1 billion possible combinations.

It turns out this confuses the model more than it helps 😅. This beeeeeegs the question....

🤔 Using an LLM to predict arbitrary identifiers, what kind of identifiers come natural to it?

Is it a question of length? Or consistency? Or the employed vocabulary? What tokens should you use? How many?

I ran a lot of experiments to get closer to an answer about all these things.

In order to enhance the performance of our model, I initially thought that the number of tokens used to represent a docid should be minimized. My rationale was _less tokens, less chances to mispredict. And while that might be true, or maybe only true to some extent, it definitely seems to be case that the employed vocabulary matters too!

I have been experimenting with different representations (or rather encodings) of the targets (i.e., the docids) -- and, spoiler, the results are actually quite impressive.

Here is exactly what I did

  1. I transform all ORCAS docids to their their SHA1 hash. This hash has 20 bytes. Because my experiment only samples 100 docids, I only took a slice of 2 bytes from that hash.
  2. I encode these 2-byte-hash-slice as, for instance, hexadecimal strings. This yields docids in the form "fc48", "7f82", ....
  3. I use the 1-query-on-100-docids experiment as a baseline to measure its top1 accuracy.

I repeat this experiment with different encodings. A full list, including some result metrics, is shown below.
(Vocab Size: Number of distinct tokens to encode 100 docids; Vocab. Sim: Mean pairwise euclidian distance between all tokens in vocabulary)

Encoding Description Example Accuracy Mean Token Length Vocab. Size Vocab. Sim.
original Original ORCAS docid D972207 0.3360 4.23 146 408
dec Integer 9958 0.3345 2.73 131 416
dec_pad Zero-padded integer 09958, 14382 0.4020 2.83 136 427
dec_x Integer with spaced digits 9 9 5 8 0.2175 5.18 11 312
dec_x_pad Zero-padded integer with spaces digits 0 9 9 5 8 0.2545 5.48 11 314
bin Bitstring 111000000100 0.2700 5.59 21 417
bin_pad Zero-padded bitstring 0000111000000100 0.3015 6.09 24 427
hex Hexadecimal encoding 0b84 0.3600 3.62 93 439
base64 Base64 encoding 07s= 0.3400 4.25 109 435
Boxplot of token lengths with each encoding

output

🚀 In this experiment, we made a 7% performance increase over our original results just by choosing a different encoding for the docids

It seems to have an easier time with numbers. Maybe it is because there exist many tokens for compounded digits (69, 420, 2001, 1944), thus reducing in less tokens needed to represent a docid.
There is an incredible 7% difference between dec and dec_pad, showing again how consistency is key! As I have already learned when trying to mix magnet links with youtube URLs, the model really suffers with inconsistent formats. And if you don't believe that the consistent char length is reflected in consistent token length, check the boxplot! It's actually kind of crazy.

Another theory I have is that having predicted a number token, based on this context it is more likely to predict another number token, and that this might help performance a little.

It is perhaps also interesting to acknowledge that number tokens are semantically very similar to each other. That goes to say the tokens for 56 and 55, or even 21, are semantically very close. Indeed, if you do k-means clustering on all token embeddings and then look for the most dense clusters, they will contains years (2012, 2013, 2014) or other numbers. 💡

We might already be very close to what the perfect (or perfectly-enough) representation is. But it might be interesting, not just for this application, but also for the broader ML community, to investigate what representations an LLM works best with. @pneague and me were thinking of using ML (genetic algorithms in particular) to learn an optimal vocabulary for representing arbitrary string identifiers. 🌈

Edit: Looking at the results again, it might just be that the model favors a low but consistent token length. But more experiments need to be conducted.

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mg98 commented May 29, 2024

Encoding of Targets

Threw away that idea of ML/ genetic algorithms to determining the best tokenization. It's not that complicated after all!

As the prior analysis already indicated (cf. boxplot in prev. comment), the LLM works best when the targets are represented in an encoding that

  1. produces a consistent number of tokens
  2. and uses few tokens

The tokenization of strings like "a3bf01..." is unreliable in the number of tokens it produces.
So, instead, I extended the tokenizer with what I playfully call poop-tokens, and I create one for every possible byte value.

CUSTOM_TOKENS = [f'💩{i}' for i in range(256)]

This makes encoding later easy as it is just a mapping of CUSTOM_TOKENS[byte value].
Finally, I get targets that look like "💩16💩201💩123💩4...", and the tokenizer has a very predictable way of operating; meaning, it will always create a consistent number of tokens.

This approach yielded the best accuracy we ever measured. For the experiment of which I listed results in the table above, this encoding yielded 42% (if I remember correctly).

Further experiments could alter the initial embedding of the poop-tokens (currently random), or compound bytes such that the length of tokens per docid could be further reduced. In this case, halved:

CUSTOM_TOKENS_2 = [f'💩{i}' for i in range(256**2)]

Practical Implications of Our Results

As we have uncovered in our last meeting, we are actually only determining the accuracy on the next unseen query, whereas most queries are likely to have been used before. In other words, we don't even know how much unseen queries are a problem, and what we win in real-world scenarios.

Therefore, I would like to include another experiment that suggests the real-world implications of our results. Queries targeting a document follow a power-law distribution (there are dozens of papers on that). What I would like to do is assume some probability distribution and map it to our dataset.

That is, instead of doing a distinct train/val/test split of the queries, I want for each set of length n to draw n queries from this probability distribution.

This approach is still flawed, however, as we ignore the degree of similarity that is correlated with the frequency of query-usage. For instance, the 2nd most used query could just be the 1st query with a typo.

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synctext commented May 29, 2024

  • You are now performing at phd level 🦄 🦄 🦄
  • Awesome progress, great shape after 12 months of work.
  • Above issue updates are at a deeper level then usual. instead of black box approach, you now dived into complex details 🎉
  • Status after 12 months:
    • 1 very thorough paper in chunking and deduplication
    • Queries is all you need 2-page writeup
    • Idea for 3rd thesis chapter: decentralised pairwise online learn to rank
  • Upcoming sprint: paperwork for http://www.graduateschool.tudelft.nl/ (reviewers from https://www.tudelft.nl/ai/design-at-scale-lab ?)

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mg98 commented Jun 17, 2024

In the last three weeks I was occupied with the re-doing of the stochastic calculations of the chunking algorithm AE, and its "cousin" RAM. The purpose of this analysis is deriving a formula in order to understand the relationship between their parameter $h$ and the expected mean chunk size $\mu$. This enables us to conduct a comparative study between all algorithms. ~added 3 page math appendix A

We're approaching 40 pages now, and thinking how to sell this work with @grimadas; Ideas of breaking this work into two papers: one survey/SoK theoretical paper, and one about the empirical study. Possible target: JSys 1st August

Draft thesis title for forms: Decentralized Machine Learning Systems for Information Retrieval

@synctext synctext changed the title phd placeholder: IPFS crawl experience, metadata, and semantic gap awareness phd placeholder: "Decentralized Machine Learning Systems for Information Retrieval" Jul 2, 2024
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mg98 commented Sep 2, 2024

Progress after this summer:

The problem is not that we failed to decentralise BM25 for 30 years. The metadata is simply not there to implement anything. So we need trustworthy metadata before we're able to realise any search.

Idea

Use LTR as a means to collect metadata from implicit cues (solves incentive problem). We propose two strategies:

  1. Local-only approach: Peer trains local model on locally generated training data only (pro: solves trust issue, personalization, con: scarce training data, cannot generalize well to unseen queries)
  2. P2P multitask learning approach: Model split in two parts: globally shared bottom (facilitated by p2p gossip) and personal layers (pro: personalization + global knowledge, con: trust is out of scope, but problem maybe a bit mitigated by still having local-only layers)

ltr draft.pdf

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synctext commented Sep 2, 2024

Comparing money and search...:There is a lack of incentives for transaction processing with double spending prevention in Peer-to-peer payments. Then Bitcoin came along, it introduced mining to make it costly to participate in a lottery. A single person selected at random from the participants is trusted to execute money transfers without fraud. Vulnerable to 51% attack, requires an honest majority. We don't have that in the metadata and decentral search world. Making a Decentral Google is harder then printing your own money 🤑 .

ToDo: polished 4 pages of article text. Only Journal submission-ready sections please. No experimental setup. No experiment description. No early results section. left for future sprints.

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mg98 commented Sep 16, 2024

First principles approach: I took some steps back to learn about the evolution of information retrieval techniques and what place learning-to-rank has in there. To that end, I found the following resources incredibly valuable:

Another interesting resource I want to share (did not read it very seriously yet, keep it for future work)

Update of LTR chapter draft (improved intro and worked on background/related work):
ltr_chapter_draft.pdf

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synctext commented Sep 27, 2024

Bit shocking to read the available papers. The state-of-the-art in decentral search and learn-to-rank makes your cry 😭 Both CASearch from 2020 and MAAY from 2006 are evidence that the Stanford-class scientists do not touch a scientific topic without any startup potential and high engineering cost. Anything decentralised is easy 100x more effort or 99% of central approaches don't work and you need to invent that 1%. Peer-to-peer is so 2001, everybody left the field.

Background reading on paper publishing versus projects in AI. Thinking two steps ahead is rather interesting advice. Top-level analysis on decentral search from 2024. Discussing the Go-NoGo moment for the Learn-to-Rank paper. Is there a need for a distraction 🤡

Please note that a phd thesis is highly specialised. It can be entirely about decentralised Learn-to-rank 💥 🤔 So, strategic thinking is indeed: which peers can we trust with privacy-preserving ClickLog info? Have a noble science goal in mind, such as "scalable models of intelligence". For great storyline we need stuff like superhuman performance of AI (their code)

Road to publishable results!
Use running code from allrank project on Github possibly.
No pause of all writing, but interleave sprints with dedicated experimental focus with a few writing sprints. Ambition level: Learn-to-rank submit by Feb 2025. {end of 2024 is much better for phd progress}
General storyline: we have this dataset, apply G-Rank+LambdaRank+ApproxNDCG+NeuralNDCG, do a novel thing, beat all other curves/algorithms. So Algorithmic work. Or valuable experimental work: move decentralised learning from an academic dream to Tribler reality. See decentral Crypto related work: NebulasRank Would need to do AI msc first, before improving NeuralNDCG. Same approach as your De-DSI work would be De-NeuralNDCG 🦄 🦄 🦄

Future paper ideas:

  • Dataset paper (performance or baseline accuracy) with peer latency, churn, privacy preserving (Our Tor fork?) User1 queries, clicks, etc. of 10k users?
  • Spam focus for learn-to-rank or search
  • All experimental work around decentral search is limited to "syntax search". Semantic decentral search is never deployed. We could do a great table of that (e.g. IPFS search, Freenet2, etc.). Search phase needs to be semantic, great other thesis chapter. This comes before the learn-to-rank (e.g. re-rank), so great for thesis coherence.

Sprint focus: De-NeuralNDCG

  • first duplicate existing work. Later sprints do your own thing. Get Allrank working with Web10k on laptop and/or Das6 The dimensionality of initial fully-connected layer was set to 96 for models trained on Web30K and 128 for models trained on Istella. Can AllRank be run on the DAS6 even with Web30k and Istella?
  • Find another Github project and identify the best ranking framework on Github
  • Comparing to central solutions ⚡ Comparing to G-Rank or MAAY ⚡ MarcelRank does best in table with 6 others ⚡ You are the baseline???

⚠️ No need for scrape, just re-usage of several years of work {OOPS, website went offline; archive.org backup}

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mg98 commented Oct 2, 2024

✨ Grand scheme thinking late at night (loose understanding of literature, take everything with heaps of salt) ✨

Inspired by my latest reads and chats in the lab, there is a vision for decentralized IR that is growing increasingly stronger in me.

The Future of Decentralized IR
... is the present of centralized IR. It is neural information retrieval techniques, such as LTR, embeddings, LLMs. Essentially, it's the global brain.

State of the Global Brain
What goes under "gossip learning" is a weird fantasy project to me. I think it's federated learning but without a central server, literally only cutting out the central aggregator node. It's not meant to be decentral in the sense that we study. The trust model isn't just missing; it's inconceivable.
DeMoE fundamentally suffers from the same problem, in addition to new problems created by the DHT architecture.

My Vision
I don't think that either gossip learning or MoE are natural! It's not how real p2p systems, and by that I mean the human2human systems that pushed our species to glory, work out information management and retrieval.
We don't learn everything from everyone and become almighty together. We also don't designate others and ourselves to become experts on specific areas of interest. No! We just live our lives, we make friends, we make experiences. And that's how I think we should approach P2P.

My Vision, but being concrete
Users should have their own brain (= model), learn from their own interactions, learn from their own files, which they will be incentivized to acquire and to study (@pneague's AI file analysis idea here) because they were intrinsically motivated to get those in the beginning. They should never let their model be poisoned by other peers. Humans don't merge brain cells with each other. We learn from interactions with our peers. We learn from future experiences whether we should trust that peer again. We know how to find information outside of our domain by asking a friend who is "semantically close to our query" or where at least their neighborhood is.

I think this vision opens the door to so many research papers, e.g.,

  • Local metadata enrichment through multimedia AI file analysis - Petrus 1st chapter
  • Web-of-trust inspired trust model based on above idea - My 3rd chapter
  • Design of a query routing protocol, also based on Petru's 1st chapter (see the Graph Diffusion Scheme paper)
  • and many more

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