(Writing this one fast just to do a quick explanation.)
One truism you learn quickly at Google is “you are not a typical user.” If you’re reading this blog, the truism probably applies to you too: you’re much more likely to be a power-user, an SEO, a librarian, or someone else who is familiar with the site: operator or the info: operator. But it’s important to remember that many Google users aren’t like that.
Bearing that fact in mind helps explain a recent change in how we handle url queries. Some people call these navigational queries, but at Google a navigational query is typing in [HP] and expecting to see www.hp.com high in the search results. A url query would be something like [www.example.com].
Previously we treated the query [www.example.com] like the query [info:www.example.com], and now we treat it like ["www.example.com"]. The query [info:www.example.com] returns the single url www.example.com if we have it in our index, along with other choices like “see backlinks for www.example.com” (I’m oversimplifying a little, but nothing too bad). The query ["www.example.com"] searches for that as a phrase, and thus returns the ten best matching urls, which will usually show www.example.com at #1 or high in the search results.
Why did we make this change? Bear in mind that you, gentle reader, are not a typical user. If super-duper power-users who know how to refine site: or info: are a set of people we’ll call N, you are probably in that set N. There is a whole different range of people M who just type in www.example.com to get to www.example.com, and who sometimes misspell the url. In math, M >> N means that M is much greater than N. That is, there are many more people who casually type in urls to get to those urls (and who sometimes misspell those urls) than there are super power users. So this change helps M. The N power users can just prepend “info:” to get to the old behavior.
Let’s take an example. Suppose the query is [www.mysace.com]. If you go visit that domain, you get a 404 error. Most likely, what happened was the user was typing [www.myspace.com] and accidentally left out the “p” from myspace. Which behavior is more helpful to that user? Here’s [info:www.mysace.com]:
Not that helpful to a user who misspelled the url or who was in a hurry and left out a letter. Now here is the new behavior for [www.mysace.com]:
Notice that the new behavior gives a suggested spelling correction, results from myspace.com, and a suggested query correction with another chance to find myspace.com. The second set of results is more likely to be helpful.
We can always tweak/refine/revert if we see problems, but this change is beneficial for many of our users, and expert users can still get the old behavior by just prepending an “info:” to their url queries.