Extension:RelatedArticles/CirrusSearchComparison

Introduction
This page shows what happens to the Cirrus Search results, used by the Related Pages feature, when we remove popularity from the factors.

With Classic Cirrus Search 2 types of score are combined: These 3 scores are multiplied together to achieve the final score. To use an example of a bad match:
 * 'SIMILARITY': A score that computes the similarity between documents, this can be fine-tuned
 * 'POPULARITY/QUALITY': A score (we call it "rescore") that use article metadata: 'boostlinks', 'boosttemplates'.
 * Boostlinks is a measure of how many articles link in, which is a mark of notability
 * boosttemplates are templates that tend to signal quality. Here is a link to the enwiki boost-templates (they vary from wiki to wiki):https://en.wikipedia.org/wiki/MediaWiki:Cirrussearch-boost-templates
 * Article: A_Summer_Bird-Cage


 * The score for "I Know Why the Caged Bird Sings" with boost links is:
 * similarity: 0.3457441 (terms chosen: "from", "cage", "bird")
 * boostlinks: 2.807535
 * boost-templates: 2
 * total: 0.3457441 * 2.807535 * 2 => 1.9413773

Below, you see 3 columns, showing results for different settings:

Community suggested list comparison, 20 Jun 2016
See phabricator.wikimedia.org/T128822#2372230

JKatz's list comparison, 20 Jun 2016
See phabricator.wikimedia.org/T128822#2372230