[new annotation proposal] Sentiment Analysis

[proycon]

FoLiA currently has the token annotation subjectivity for limited sentiment analysis or other subjectivity annotation, it is used by the VU-DNC corpus for instance. This, however, is not sufficient for more complex expressions of sentiment. A strong span annotation element is needed. The following proposal is inspired on NAF's opinion layer:

<s>
 <w xml:id="w1"><t>He</t></w>
 <w xml:id="w2"><t>is</t></w>
 <w xml:id="w3"><t>happy</t></w>
 <w xml:id="w4"><t>to</t></w>
 <w xml:id="w5"><t>see</t></w>
 <w xml:id="w6"><t>him</t></w>
 <w xml:id="w7"><t>.</t></w>
 <sentiments>
  <sentiment class="emotion.joy" polarity="positive" strength="moderate">
    <source>
      <wref id="w1" t="he" />
    </source>
    <target>
      <wref id="w6" t="him" />
    </target>
    <hd>
      <wref id="w3" t="happy" />
    </hd>
  </sentiment>
 </sentiments>
</s>

This predefines the following feature subsets, whether they are actually used and the class values they take are defined by the set.

• polarity
• strength

The following span role elements are introduced and used (will be reused in another upcoming proposal as well):

• source - The source/holder of the sentiment (optional)
• target - The target/recipient of the sentiment (optional)
• hd - The head contains the sentiment itself (required)