Steve Baker, an engineer in the search quality group at Google, just did a nice post about synonyms on the Google blog. A lot of people seem to think that Google only does simple-minded matching of the users’ keywords with words that we indexed. The truth is that Google does a lot more sophisticated stuff than most people realize. I’d say that Google does more with “semantics” and both document and query understanding than almost any other search engine.
Read the blog post for more info, but I liked a couple examples that Steve mentioned. “Pictures” and “picture” often mean the same thing, but the query [arm reduction] is very different than [arms reduction]. Also, in the query [dura ace track bb axle njs] the “bb” is probably referring to a bottom bracket while in the query [software update on bb color id] the “bb” probably means blackberry.
Still not convinced? Here’s some new stats from Steve that we haven’t made public before:
However, our measurements show that synonyms affect 70 percent of user searches [note from Matt: of course, it could be a subtle change] across the more than 100 languages Google supports. We took a set of these queries and analyzed how precise the synonyms were, and were happy with the results: For every 50 queries where synonyms significantly improved the search results, we had only one truly bad synonym.
I hope Google continues to open up more about search quality and talk more about our search rankings. Steve is a smart engineer. I love that Google has a lot of smart engineers like Steve and with any luck we’ll continue to highlight the sort of work that those engineers do.
As far as concrete advice for webmasters, the same advice still holds that we’ve always said: think about the different words that searchers might use when looking for your content. Don’t just use technical terms–think about real-world terms and slang that users will type. For example, if you’re talking about a “usb drive,” some people might call it a flash drive or a thumb drive. Bear in mind the terms that people will type and think about synonyms that can fit naturally into your content. Don’t stuff an article with keywords or make it awkward, but if you can incorporate different ways of talking about a subject in a natural way, that can help users.
Added, Jan 22, 2010: Another nice post on the Google blog, this time about highlighting users’ answers directly in search result snippets.