To make the best use of today's search engines the user must first deduce good keywords to search with. Coming up with good keywords, however, without first wasting a lot of time first searching pages for the most appropriate keywords, is a matter of luck, intelligence, and experience. If you're clever, if you spend a lot of time on the web, and if you know how the people who create the data you're currently searching for think, then your queries are going to be much more exact and efficient than otherwise. In other words, you can only come up with good keywords when you already know more or less what's out there. Almost all of the search effort is placed on the user's shoulders and not on the computer's.

Ideally, you should be able to ask your computer, "Get me the name of that Chinese spice that smells like parsnips" rather than have to wander around some virtual Chinese grocery. The problem with asking, however, is that search engines are non-contextual. Their answers often mingle a few interesting pages with many uninteresting ones. Extracting those few good pages out of the swamp of irrelevant pages is hard work.

Lacking the intelligence to establish a good idea of the user's particular context, today's search engines rely on raw keyword occurrences to answer queries. Further, they pay no attention to the context of the user's previous queries to better answer the user's current query. Finally, the answers they provide will likely become less and less useful as the web continues to expand in volume, variety, and volatility.

Locality, however, gives context cues to the search engine for free. Once you're in a Chinese grocery, then asking the same spice question there is much more likely to get you what you want because there is more context for the system to use. Given enough context, even a dumb agent can produce smart answers.

Locality is also a good idea because it helps the system answer negative questions. If you search the entire neighborhood dealing with a particular topic and find nothing then you would know that the sought for data is not out there. Without context, you are left in doubt about whether the data isn't there or whether it's there but the keywords you selected were inappropriate to pinpoint it.