The search engine updates are aimed specifically at growing the list of relevant Web sites in Yahoo's search index, said Tim Mayer, director of product management for Yahoo Search. The company is also in the midst of tweaking its search algorithm, which determines the ranking of search results, he said.
The update, which began Wednesday, is a work in progress that won't be complete for another week or two, Mayer said. He urged Webmasters to be patient until the process is complete.
"We need to ensure quality results for our users," Mayer said. "If we feel that this is a much better experience for our users, we feel it's the right thing to do."
But some Webmasters are already voicing concern about the changes in online message boards and Web logs. Some are grumbling that their sites no longer appear in search results pages. Others complain the revised engine is overrun with illegitimate results.
"Riddled with spam--worse than before--yecch," Jason Bailey wrote on Yahoo's own Web log about new search developments. "And you removed a couple of great sites of mine. I recommend a rewind to May's results. The last two rollouts have been a heyday for the (search engine results page) spammers and a disaster for many legit merchants."
"I do hope this is not the end," wrote an anonymous contributor to the WebmasterWorld.com message board. "So much spam has crept back in."
But many others say they've benefited from the changes.
"After nearly six months of just the home page indexed on one of my most recent sites, today Yahoo displays 242! This is great!" wrote another anonymous WebmasterWorld.com contributor.
Many Webmasters count on search engines to generate traffic and business for them for free. A change in the way Yahoo, Google and others rank search results can damage their livelihoods and provoke impassioned protests. For instance, WebmasterWorld.com, one of the most active message boards on the subject of search, showed more than 153 comments on the new Yahoo search engine changes, in a 16-page thread.
The volume and tone of the comments are not unusual or surprising, Yahoo's Mayer said.
"We do care about this community, and we try to keep open communication with them, he said. "But when they lose traffic, they're going to complain."
The search engine update is the third major one for Yahoo this year. The company began notifying Webmasters of significant changes this year on its Web log, Mayer said.