Yahoo!’s new RSS search site was introduced to the public domain this morning. Yahoo! RSS Search is no longer exposed outside the firewall so don’t be surprised if you are redirected to Yahoo! Search when you follow the aforementioned link. This early version of a future Yahoo! search component appeared to restrict searches of Yahoo! Search’s index to only include content published as a feed. I presume Yahoo! will use RSS as a generic term referring to feeds including RDF, RSS, and Atom.
Yahoo! RSS Search features the ability to order your results by time, relevance, or by popularity. Sort by relevance most likely utilizes the same ranking algorithm as general Yahoo! Search. Sort by popularity may be based on inbound links on a per-page basis, inbound links on a per-site basis, or Yahoo!’s proprietary site ranking. You can also restrict your search to just the RSS feeds in the My Yahoo! database.
The Yahoo! RSS Search home page mentions that Yahoo! intends to highlight works licensed under Creative Commons in its search results.
Yahoo! has a lot of good data inputs for a solid database of feed content. Mix blo.gs ping notifications with My Yahoo! usage statistics and Yahoo! Slurp‘s crawl abilities and you have update information, usage information, and a robust crawler to index HTML content and even enclosures using Media RSS or common file formats such as Word or PDF documents.
I also wonder what happens when terms like “relevance” are publicly used to describe a search method. No one likes to be told their piece of published content is not very relevant.
I expect to see more companies like Yahoo! adding vertical search front-ends to their massive indexes to attract new users and focused advertising dollars. It would be interesting to see Yahoo! Search Subscriptions extended to the personal publishing realm. It’s always interesting to take a peek at web applications in the alpha stage of development.