Here are the results of some recent research where I analysed nine major search engines and deep websites.

Each number in the first column is a Dewey Decimal code. The subject description for each code can be found here.

To get these results, I generated representative terms for each Dewey Decimal code, then sent them to each search engine. I then normalised the results and assigned a score to each search engine.

This research can be applied to any search engine, database, or collection of text.