OPAL is a Drupal plugin that analyses comments posted by users and detects whether they are positive, negative or neutral. In addition, it calculates the joint polarity of all comments attached to a content type and deliveries an overall rank for the post.

The goal of the application is to show how opinion mining can aid in assessment of content such as ideas in Idea Management Systems.

Info: Opinion mining app, that analyses comments and determines if they are positive or negative.
Quick Links:
Demo: ETSITIdeas (default) | ETSITIdeas Int. (themed)

Screenshot of an unthemed Drupal instance with OPAL installed.

By default OPAL will add snippets to all content types and comments.

For content types it will display:

  • An image that visualises balance between emotions expressed in all comments
  • Overall polarity score together with percentage of positive/negative/neutral posts
  • Amount of positive, negative and neutral posts

For each comment:

  • An image that visualises the sentiments in the comment (positive, negative or neutral)
  • Polarity score

In each case the amount of information that is shown can be customized in module settings (Site Configuration/Opinion Analyser). All the information can be themed with CSS (see module directory) but is also passed in $node and $comment objects for more advanced theming. In addition, OPAL is supported by RDFme so its possible to export the opinion mining data along with other information into RDF/XML.

The opinion mining algorithm that we used is very simple and does not aim to achieve great accuracy, the point of the application is to be a proof of concept for Idea Management Systems. To see a demo of OPAL in action take a look at our ETSIT Ideas International instance built with Gi2MO IdeaStream that customizes OPAL widgets to display the opinion statistics in a more subtle way.

Online Demo Access: ETSIT Ideas (default theme) | ETSIT Ideas International (IdeaStream Theme)
OPAL Manual (spanish only): opal_manual.pdf
Source Code:
Dev Page: Drupal project page for OPAL

Previous Versions:
Opal v1.3.1: