Niall Kennedy at Technorati has just informed me that they have quietly updated their tag search engine with full boolean search functionality.
In August, Technorati added the OR function to tag search. On a search for “apple OR microsoft”, the results would include any posts that included either tag. While useful, this functionality essentially just reduced the number of searches a user needed to perform to find posts with relevant information.
They’ve now added AND and NOT functions, which significantly help narrow result sets for specific searches. For instance, a user looking for blog posts on both Microsoft and Web2.0 (89 results) can now easily find those results, instead of sifting manually through a much larger result set for just Microsoft (16,627 results) or Web2.0 (5,717 results). Technorati has in an instant just given the user the 89 results that he or she really cares about.
The NOT function is just as useful. Want to refine the result set above even more? Try “microsoft NOT office NOT windows NOT msn AND web2.0” to narrow it down to just 66 results.
Yes, these are advanced functions, but as the number of blog posts continues to skyrocket and publisher tagging is becoming more ubiquitous, users need tools to quickly refine result sets and find what they are looking for. By adding this functionality, Technorati made tagging more valuable.