Tuesday, March 11, 2008

New Search Feature: "opt:nostem"

In the science of Information Retrieval there's a constant tug of war between precision and recall. As Wikipedia defines the terms, precision is the fraction of the documents retrieved that are relevant to the user's information need, and recall is the fraction of the documents that are relevant to the query that are successfully retrieved. Or as I define the terms, precision is how much of what you wanted you actually got, and recall is how much of what you got is what you wanted.

MarkMail increases recall by running stemmed searches. This loosens the query constraint so that searching for proxies will match proxy as well. Sometimes this is good, and sometimes we hear from users who don't like the behavior all that much! They want more precision.

So we're happy to announce a new feature, opt:nostem, that when added to the search string turns off stemming for that query. You can try it for yourself:

http://markmail.org/search/?q=proxies
http://markmail.org/search/?q=proxies+opt%3Anostem

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