Kiran Bhadury, Vishal Chakraborty, Francois Demoullin, Norm Matloff, Monte Misa, Rylan Schaeffer, Tiffany Ching L Yuen
Norm MatloffArnav Acharyya, Matt Donnelly, S. Ismail, Lan Jiang, Sachin Kumawat,
Thong Le, Chase Maguire, Darya Semyonova, Sana Vaziri
- What is OMSI?
- 5-Minute Quick start for students and instructors:
- Benefits for students
- Benefits for instructors
- How to use this package
- Software tools for grading
- Future enhancements
(In addition to the quick steps below, there is a fully worked-out example for an exam using the R language in a README file included in this package. You need not know R to follow the example.)
You'll need Python 3.0 or higher on your machine.
Here you will start the server (normally done by the instructor); start the client (normally done by the student); play the role of the student, working a quick exam problem and submitting it to the server; and play the role of the instructor, inspecting the student's submitted work.
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If you know git, just clone the OMSI repo. Otherwise, go to the repor and download the .zip file (Clone or download | Download ZIP), and unzip it,
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In a terminal window, change to the resulting directory/folder omsi-master. You should see files OmsiServer.py etc.
Use this terminal window for the server. -
From the same directory/folder, open a second terminal window, this one for the client.
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In the first window, start the server, say at port 2000 and exam name 'abc':
$ python OmsiServer.py 2000 abc
- In the second window, start the client, say with student ID me@xyz.edu and exam code 88 (ID and code fake for this dry run):
$ python OmsiGui.py localhost 2000 me@xyz.edu 88
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In the client GUI that comes up, choose File | Connect. Click Enter in the dialog box that pops up.
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In the GUI, you'll now see a sample exam that comes with the package. Choose some question that asks you to write code.
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You'll see the question in the upper-right box. Type the answer in the lower-right box.
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Choose File | Save and File | Submit & Run. A dialog box will pop up, reporting that the file was successfully submitted to the server, and the code will be run in another dialog box, showing the output.
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Exit the client, File | Exit. To see that your submitted answers (note plural) are indeed there at the server, enter the directory/folder InstructorDirectory/abc/me@xyx.edu, and observe that there it is, in the file omsi_answer2.py or whatever.
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Kill the server by hitting ctrl-C.
Note that since you had the host and client on the same machine, the host was 'localhost'. On a real exam, the instructor announces the location of the server, and the students use that instead of 'localhost'.
IMPORTANT NOTE: The students may need a VPN to access the server. If so, they must keep this in mind when starting up OMSI.
OMSI, short for Online Measurement of Student Insight, is a software tool for conducting and grading examinations in a manner that is both secure and conducive to high-quality measurement of student insight. It is suitable for small or large class exams, be they based on essays, writing code or math analysis. This is NOT a "Scantron multiple choice test administration tool."
Students come to the classroom at the regular class time, just as with a traditional pencil-and-paper exam. However, they use their laptop computers to take the exam, using OMSI. The latter downloads the exam questions, and enables the students to upload their answers. Most importantly, use of the laptop enables the student to actually do his/her exam work on the laptop.
As detailed below, this arrangement has significant benefits for both students and instructors. The system is easy to install and use, and can be run on Macs, Windows and Linux.
In the case of exams in programming classes, OMSI is especially valuable:
OMSI enables the students to compile/run their code, thus giving them an opportunity to discover and fix errors. I often give them the intended output, for instance, and if their code doesn't match it, this feedback allows them to think about where they went wrong (whether a logic error or lack of understanding of the concepts in a math problem). This thus gives them a chance to give the problem more thought and hopefully correct their code.
Note that even in math courses, the programming feature facilitates giving exams online. Instead of being limited to multiple choice, the exam can have the student present the answer as program code, e.g. in R,
3*x^2for 3x2. OMSI also allows display of graphics in R.
Below is a screenshot of an example screen from the student's point of view.
The details will be presented below, but even now the basic layout is clear: In the left panel, the student chooses which exam question to work on; the question itself is shown in the upper-right panel; and the student writes the solution in the lower-right panel, whether it be code, math or essay.
Dear students:
OMSI will often result in your getting a higher grade in an exam than you would have in the traditional pencil-and-paper format:
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With essay questions, you have a chance to edit your answers, producing more coherent, readable prose. No cross-outs, arrows, words squeezed in above a line, no points off for unreadable handwriting. :-)
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With coding questions, you will compile/run your code using OMSI, giving you a chance to make corrections if your code doesn't work.
In both of these aspects, OMSI gives you a better opportunity to demonstrate your insight into the course material -- and thus achieve a better grade -- compared to the traditional exam format.
Dear instructors:
OMSI will make your life easier. :-)OMSI facilitates exam administration and grading. It has two components:
- Exam administration:
OMSI manages the actual process of the students taking the exam.
You get electronic copies of the students' exams, eliminating the need for collecting and carrying around a large number of papers, and making work sharing much easier among multiple graders.
At the end of an exam period, there is no chaos, e.g. from students who are still writing even when the period is over; the instructor merely shuts down the server at that time, and nothing further can be submitted.
If a student wishes his/her performance on an exam problem to be reassessed, the fact that the files are online means that the instructor can check the student's work from anywhere, rather than having to wait for the next visit to the office.
As noted in "Benefits for students" above, OMSI enables the student to turn in a better product, and this benefits the instructor as well: Better exam performance by students is both more gratifying to the instructor and also makes for easier, less frustrating grading.
- *Exam grading:* OMSI does NOT take the place of instructor judgment in assigning points to exam problems. But it does make things much easier, by automating much of the drudgery. For instance, OMSI automatically records grades assigned by the instructor, and automatically notifies students of their grades via e-mail. Gone are the days in which the instructor must alphabetize the papers, enter the grades by hand, carry an armload (or boxload) of papers to give back to students in class, retaining the stragglers not picked up by the students, and so on.
Contents:
- Terminology
- Installation (instructors and students)
- Directions for students
- Directions for instructors
The Linux term directory is synonymous with folder for Mac and Windows.
The Mac/Linux term terminal window is synonymous with Command Prompt for Windows (cmd command).
You will need Python 3.0 or higher installed on your machine. For Mac and Linux systems, it may already be there, but it is easily downloadable for Windows.
You must have Python in your executable search path. To check this, open a terminal window and type
python
in a terminal window. Python should start, displaying the >>> prompt. (Exit via ctrl-d or by typing 'exit()'.) If you have both Python 2.7 and 3 on your system, you will need your login file, e.g. .profile for bash to give priority to version 3. Note: OMSI, which runs in Python, will itself invoke Python. Thus Python 3 must come first in the search path.
In the case of exams involving coding, the same statements above about search path and so on apply to compilers (e.g. gcc) and other interpreters. For example, if your exams will be using R, open a terminal window and type
R
in a terminal window. (Start R directly in this manner, not from RStudio or the R screen icon.) R should start, displaying the > prompt. Exit via ctrl-d or by typing 'exit()'.
Make absolutely sure Python and R can be run from the command line as above.
To install OMSI, download the .zip file from the OMSI site. Unzipping it will produce a directory/folder omsi-master, where all relevant files reside. We'll call this the OMSI Home.
Connect to the server, at the start of the exam:
Assuming you installed the package earlier, open a terminal window, change to the OMSI Home, and run
python OmsiGui.py
Then connect to the server and get the exam questions by selecting File | Connect. State the host, port and exam code provided by the instructor, and your student e-mail address. (You can also type them as command-line arguments; see below.)
After you connect to the server, the exam questions will be downloaded to your machine.
NOTE: There should be two separate windows on the right of the GUI, one on top for the question prompt and one below to write the answer. The boxes are resizable and the question box may default to occupying most or all of the right side of the screen on some systems. If this is the case grab and drag up the bottom of the question box to expand the bottom window. The boundary between the question and answer boxes may actually be hidden by your OS toolbar at the bottom of your screen; if so, resize the entire window first, then drag it upward so that the boundary line is visible.
You have the option of specifying needed information on the command line instead of later into the GUI. For instance:
python OmsiGui.py xyx.edu 2000 me@abc.com Midterm1
(You need not specify all of these on the command line, but the ones you do specify must be in order, nothing skipped.)
In addition, if your instructor allows it, you may specify a PDF file of material to help you. See below.
Copy-and-paste:
In programming classes, the instructor may wish to place a template, i.e. an outline of the answer, in the question box, with students filling in the gaps in the code. Copy-and-paste operations using a mouse may depend on the type of machine/OS used. Instead, OMSI offers a CopyQtoA selection in the menu, which completely copies the contents of the question box to the end of the answer box. Students then edit. (You may need to scroll down in the answers box to see the copied material)
Saving answers:
Click the question number on the left of the OMSI screen, and select File | Save. Note that saving is NOT submitting to the server. Saving your file does NOT upload your answer to the instructor's server; the save operation merely saves to a file on your local machine. See "Submitting your answers" below for uploading to the instructor. Note too that Save saves your answer to the current problem, not all of the problems.
By the way, your answer files are saved locally in your OMSI Home directory, i.e. the same directory from which you launched OMSI, with file names beginning with 'omsi_answer', e.g. omsi_answer2.txt. This can be useful if you want to check later what you submitted.
Compiling/running code:
Save the code first. Then, if the problem involves a compiled language such as C, select File | Compile. A new window will pop up, confirming that your submission was received at the server, and then (possibly after a short delay) another window will pop up to display the results. Then select File | Submit & Run (or for an interpreted language like R or Python, go to this step directly, no compile step). A new window will pop up, displaying the results.
OMSI has the capability of displaying R graphics. See below.
Submitting answers:
Submit the answer to a particular question by clicking on the question number on the left side of the OMSI screen, and selecting File | Submit. This will upload your answer to the instructor. A dialog box specifying whether submission was successful will then be displayed.
Note again that clicking the Submit only submits your answer to the problem you are currently working on, not all the problems.
IMPORTANT: There may be a delay of a few seconds before the submit operation completes and the confirmation box comes up. Do not perform any OMSI operations while waiting for this.
Note:
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Each time you run your code, it is automatically submitted to the server.
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Each time you submit your solution to a question, the new solution overwrites the old one, both locally and on the server.
Viewing a PDF file for consultation:
The instructor may allow you to consult a PDF file to help you during the exam. In my case, for instance, my exams are open-book, and the book is in the form of an open-source PDF file, so this OMSI option makes the book available to my students during exams. Or your instructor may provide you with a PDF "cheatsheet," say containing important formulas.
To view the PDF file, select File | View PDF. Note that in order to use this option you must specify so in the command line when launching OMSI, e.g.
python OmsiGui.py xyx.edu 2000 me@abc.com exam2 "open abc.pdf"
for a consultation file abc.pdf. Depending on your OS, you might have a different command to open the PDF file than open, e.g. evince on a Linux system.
Viewing an R or Python help file:
Depending on your OS, you may be able to view help files from within OMSI.
For instance, say you are using R in an OMSI exam question, and have forgotten how to use R's rbind() function. Simply place
help(rbind,help_type='text')in your answer window, and hit Submit & Run! For some OSs, you may need to try type='pdf' or type='html'. Of course, you should determine the proper argument for your system before you take your first exam.
Also, in R a line like
args(rbind)should work independent of your OS, to do a quick check of the required arguments for a function.
Viewing output of R graphics:
If, say, you call hist() to form and display a histogram, R will write the output to a file Rplots.pdf, since it does not know of a screen to display on. You can view the plot by clicking File | View R graphs, provided you specified a PDF viewer when you launched the OMSI client (see above).
Properly used, you will find that OMSI provides the instructor with a more accurate assessment of your insight into the course material, i.e. you get a better grade. But you do have to keep in mind the following.
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Make SURE you are prepared: Be sure to try OMSI in an actual session before your first OMSI-based exam. Start up the server, playing the role of the instructor (see "Directions for instructors" below), and then start the client, playing the role of the student as above. (Note: If you run the server on your local machine, specify the server location as 'localhost'.)
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Make sure your laptop can connect to your school's WiFi system.
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Make sure your laptop is fully charged before the exam.
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It is good to remove your old answer files (their names begin with "omsi_answer") from a previous exam before starting the current one.
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In programming classes, make absolutely sure that your software is configured properly. For instance, with R, make sure that typing 'R' in a terminal window does start R.
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Starting OMSI: Make sure you launch OMSI from your OMSI Home directory.
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Submitting your answers: Submit your answers often. Near the end of an exam period, the network may be very busy, possibly making it difficult to get in. Note that each submission will overwrite the last.
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Remember that saving an answer does NOT submit it. You must do that separately.
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Following your instructor's directions: When you begin the exam, your very first action should be to click CLICK HERE FIRST. The instructor may have directions there that will make a night-and-day difference in your grade! So first take a few seconds to read this.
Tips for programming classes:
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If your exam tests you on Python or R, remember that they won't be running in interactive mode here, so you must write explicit print operations. Graphical displays will not work, for the same reason. (See the R workaround, above.) Note too that these are not compiled languages, so you should not hit the Compile button.
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If you have a runtime error, the output of your print statements may not be displayed. You can remedy this by placing a return statement or similar before the line of the runtime error.
Other tips:
- If your instructor allows you to use OMSI's PDF viewing option, use a PDF viewer that has a good search facility, so that you can quickly find what you need during an exam.
Within the OMSI Home directory, there will be a subdirectory named InstructorDirectory. You place your exam questions in that directory, in a file Questions.txt. The format for specifying the questions is detailed below.
The Questions.txt file:
Upon startup of the server, a subdirectory of InstructorDirectory will be created for this exam, and within it there will be a further subdirectory for each student, using the e-mail address provided by the student. In a student's subdirectory there will be an answer file for each question. e.g. omsi_answer1.txt or omsi_answer2.java
Known issues:
As of the current version, the server may have trouble with downloading very long files on some networks. It is best to keep the Questions.txt file to under 3000 bytes. The same is true for SuppFile, etc.
I usually run the server on a machine in our student computer lab, using ssh to remote login to the lab computer. (It can also be run on the instructor's laptop computer, providing the latter is configured to be a server. See "Tips" below.)
At the start of the exam period (not before), start the server from a terminal window by issuing the command
python OmsiServer.py portNumber examName examCode
from within the OMSI Home directory, e.g.
python OmsiServer.py 5000 Midterm1 breadbox
The port number must be at least 1024.
This will create a directory Midterm1, in which the students' submitted answers will be stored.
The server Internet address, port number and exam code (no embedded spaces) will need to be announced to the students at the start of the exam.
At present, this is simply done via ctrl-C.
Before the exam, the exam questions must be placed in a file called Questions.txt in the InstructorDirectory. The file should contain a description and the questions for the exam. If there are notes the instructor would like to write to him/herself in the file they can be placed at the beginning, in the section labeled NEW.
When parsing the file, OMSI will go through line by line and search for keywords NEW, DESCRIPTION or QUESTION. The roles are as follows:
- NEW: Optional. The lines that follow will contain private notes for the instructor.
- DESCRIPTION: Required. The lines that follow will contain instructions to students, which would normally go on the front page of a printed exam, say "You will have 50 minutes for this exam." . The students will be able to view it by clicking the CLICK HERE FIRST button in the menu.
- QUESTION: Have one of these lines for each exam problem. For problems involving code, directions for compiling or running the code go on this same line. The lines that follow this line contain the question, to be viewed by the students.
Example Questions.txt file:
DESCRIPTION
You will have 50 minutes for this exam.
QUESTION -ext .py -run "python omsi_answer1.py"
Write a Python function half() that will return x/2, and
freestanding code will print half(3).
QUESTION
What does 'D' stand for in "UCD"?
In this example, two exam questions are defined, one requiring Python code and one requiring an essay. When a student writes and submits the answers, they will be saved in files omsi_answer1.py and omsi_answer2.txt in InstructorDirectory at the instructor's server, in the current exam directory, and in that student's subdirectory (indexed by e-mail address or other student ID).
The suffix in that first file name arises from the specification -ext .py in the QUESTION line; otherwise the default suffix is .txt,
The -run field tells OMSI how to run a student's code. This will be invoked when the student clicks Submit & Run, and later when the exam is graded, if the instructor uses the OMSI grader.
Specifying compile and run options
There are various QUESTION line options for the case of compiled code. For instance, Question 1 might have a line
QUESTION -ext .c -com gcc -flags "-Wall -g" -run ./omsi_answer1
OMSI will compile the student's code using gcc, taking omsi_answer1.c as input, and if the compilation is successful, it will produce the executable file omsi_answer1. The -flags field is mandatory. (Students running OMSI within a virtual machine may have a problem with -Wall, so the instructor may wish not to use this flag.)
Here is one for R, for a Question 3:
QUESTION -ext .R -run 'Rscript ./omsi_answer3.R'
Note that fields with embedded spaces must be quoted.
Vital note: Do not touch the same Questions.txt file with both a Windows machine and a Mac. It is well-known that such mixing of machines on the same file can cause corruption in the contents; see the details.
OMSI should greatly improve the examination process for both instructors and students. However, as with any automated system, some care is needed to insure that things run smoothly.
In familiarizing yourself with OMSI, do a trial run, playing the role of both instructor and student. Start up the server as the instructor, then take the exam as a student. Look at the files that are then produced at both the server and client ends.
Making sure the students know the procedures:
It is crucial that the instructor, before the first OMSI-based exam, require the students to go through a dry run. The instructor may wish to incentivize this. The instructor can nudge the laggards who haven't gone through the dry run (as evidenced by the lack of submitted files from them).
Dealing with exam time constraints:
If the exam involves coding, it's hard for a student to write full code within an exam period. What I like to do is give the students partial code in the question, and have them fill in the missing lines, and/or modify existing lines. Clicking the CopyQtoA button will copy the contents of the question window to the answer window, so students need not type in the provided partial code.
Exigencies:
"Stuff happens." What if, say, there is a sudden power failure or the local WiFi access point suddenly goes out? What if some students do not go through the dry run, even with major incentives/disincentives, and have trouble using OMSI in the first exam? The following are worth considering:
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Paper copies of the exam prompt should be distributed at the start of the exam, and students should have the option of turning in their answers on paper. Some students may not even have laptops (though it should be emphasized to students that they do NOT need a "fancy" laptop; an old and slow one is fine).
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Students should be told to click the Submit option "early and often." (Each submission will overwrite the last.) This is especially important if there is concern that the local WiFi access point might be flooded with traffic at the end of the exam period, as many students turn in last-minute work.
There is currently a 20-second timeout setting for client transmissions to the server. After that, the client will try again. Note that on Mac machines, the "spinning rainbow disk" will appear after a few seconds. This should not cause alarm in the students; it will disappear when the client is finally able to contact the server. If desired, though, the student can kill the OMSI client and restart it; the previously-saved answers will still be there.
The instructor may also consider running two (or more) servers, in order to improve response time.
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Students should bring a USB key (thumb drive, memory stick). In an emergency, they can copy their local copies of their omsi_answer* files to the key, then turn in the key.
Where to run the server:
I usually run the server on a machine in our student computer lab, which gives me a static IP address. I use ssh to remotely log in to the server from the classroom, and start the server at the appropriate time. Depending on configuration, ssh may time out after a certain time, so I run screen and run the server within a terminal window there (Sachin's idea). I also run script at the server, to get a full record of all transactions, possibly of great use if there is suspicion of cheating.
In other words, I issue commands like this example:
ssh pc22.cs.ucdavis.edu
cd omsi.home # wherever OMSI Home is
screen
script Midterm1
python OmsiServer.py 2000 Midterm1
ctrl-a, ctrl-d # exit 'screen'
exit # leaving pc22
ssh pc22.cs.ucdavis.edu # preparing to shut down server, end of exam
screen -r # resume 'screen' (but server has been running all along)
ctrl-c # kill server
exit # end 'script', have record now in Midterm1 file
exit # end 'screen'
exit # leave pc22
Running the server on a laptop:
For experts only!
The instructor could run the server on a laptop computer in the classroom. However, this gives a dynamic IP address, basically visible only to other machines using the same router. The students' laptops must thus also go through the same router. This should be fine as long as the instructor and students are both using the university's WiFi access, but it must be carefully tested beforehand. Note that this approach may be more secure. Obtain the server's IP address via the ifconfig command for Mac or Linux, ipconfig for Windows.
Cheating:
What about cheating? In my experience, the vast majority of students are honest, and they resent the cheaters. What can be done about the latter?
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The OMSI window is designed to fill the student's entire screen. This prevents a student from communicating with others electronically during the exam, say by e-mail. The students must be given strict instructions not to move, iconify or resize the OMSI window during the exam. This is easily monitored by proctors.
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As usual with any type of exam, there is the problem of a student looking at his/her neighbor's work, in this case a laptop screen rather than a piece of paper. A common technique for dealing with this in the paper exam case is to require students to sit in specific seats that are randomly assigned to them, in order to prevent collaboration among friends. One can also have an exam question that requires each student to state who her left and right neighbors are. These measures can be taken with OMSI as well.
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If the server is run through a static IP address, it is conceivable that a dishonest student will take the exam at a location not in the classroom, thus enabling illicit "consultation" by hiring, say, dishonest graduate students for help. Sign-in sheets, taking photos etc. can be used to avoid this. Note that the server will record the transactions by the students in the 'script' file in the exam directory (if run as above). Use of an exam code, especially a longer one not easily guessable or easily sent surreptiously by cell phone, is a major preventing remedy. Needless to say, use of cell phones during the exam should be strictly forbidden.
I have a set of groundrules that instructors may find useful.
The answers submitted by the students and collected by the server may be graded by hand as usual. However, tools to facilitate electronic grading are available in this package. As noted earlier in this document:
OMSI does NOT take the place of instructor judgment in assigning points to individual exam problems. But it does make things much easier, by automating much of the drudgery. For instance, OMSI automatically records grades assigned by the instructor, and automatically notifies students of their grades via e-mail. Gone are the days in which the instructor must alphabetize the papers, enter the grades by hand, carry an armload (or boxload) of papers to give back to students in class, retaining the stragglers not picked up by the students, and so on.
The basic idea is that the grading software will display on the screen, for each student and each exam problem, the student's answer. In the case of coding questions, the software will also run the code and display the result. In each case, the instructor then inputs the number of points he/she wishes to assign. In summary, OMSI runs
for each student:
for each exam problem:
if problem involves coding:
compile and/or run code according to the
QUESTION line of Questions.txt, displaying result
display student answer
instructor inputs number of points
record grade for this student (individual problems and total)
The main tool is Grading/AutoGradeOMSI.R. This code is in R, as it is an adaptation from an earlier system I had developed. Also, R's statistical and graphic capabilities facilitate analysis of the exam grades. (There is also a file AutoGrade.py in that directory, but it is under development.)
Detailed directions are given in the comments at the top of the file.
Much improvement is possible. Contributors of new code are welcome!
Here are some points of improvement:
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Tablet-friendly version of OMSI.
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Authentication code to check a student's e-mail address against a class list upon connection, with passwords being required.
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Code to confirm the integrity of the OMSI client code (i.e. verify that the source code hasn't been changed), and to upload each student Submit & Run operation to the server, to guard against the student running surreptitious communication code.