Editing Encyclopedia:Search engine test (section)

==Search engine tests==
Depending on the subject matter, and how carefully it is used, a search engine test can be very effective and helpful, or produce misleading or non-useful results. In most cases, a search engine test is a first-pass [[heuristic]] or "[[rule of thumb]]".

===What a search test can do, and what it can't===
A search engine can index pages and text which others have placed on the internet, just like a big index at the back of a book.

'''Search engines can:'''
* Provide information and lead to pages that assist with the above goals
* Confirm "who's reported to have said what" according to sources (useful for neutral citing)
* Often provide full cited copies of source documents
* Confirm roughly how popularly referenced an expression is. {{em|Note, however, that Google searches may report vastly more hits than will ever be returned to the user, especially for exact quoted expressions.}} For example, a Google search for "the green goldfish", with quotes, in 2021 initially reports around 209,000 results, yet on paging through to the last search results page shows the returned number of hits to be 303. See also [[Wikipedia:Reference_desk/Archives/Mathematics/2008_August_29#Statistics_-_How_can_i_test_for_the_existence_of_a_significant_difference.3F|here]] to calculate statistical significance.<ref>For example, if there are 16 hits at Google Books under one name, and 24 under another, there is only a 70% confidence that the second name is actually more common.</ref>
* Search more specifically within certain websites, or for combined and alternative phrases (or excluding certain words and phrases that would otherwise confuse the results).

'''Search engines cannot:'''
* Guarantee the results are reliable or "true" (search engines index whatever text people choose to put online, true or false).
* Guarantee ''why'' something is mentioned a lot, and that it isn't due to [[online marketing|marketing]], reposting as an [[internet meme]], [[spam (electronic)|spam]]ming, or self-promotion, rather than importance.
* Guarantee that the results reflect the uses you mean, rather than other uses. (E.g., a search for a specific John Smith may pick up many "John Smiths" who aren't the one meant, many pages containing "John" and "Smith" separately, ''and also'' miss out all the useful references indexed under "J. Smith" or, if the term is put in quotes, "John Michael Smith" and "Smith, John")
* Guarantee you aren't missing crucial references through choice of search expression.
* Guarantee that little-mentioned or unmentioned items are automatically unimportant.
* Guarantee that a particular result is the ''original'' instance of a piece of text and not a reprint, excerpt, quotation, misquotation, or copyright violation.
and search engines {{em|often will not:}}
* Provide the latest research in depth to the same extent as journals and books, for rapidly developing subjects.
* Be [[WP:NPOV|neutral]].

A search engine test {{em|cannot help you avoid}} the work of [[#Interpreting results|interpreting your results]] and deciding what they really show. Appearance in an index alone is not usually proof of anything.