Google's ever active search bots, which scour the Web constantly for new pages, have begun a new, more active phase of their indexing jobs.
In a blog post Friday, Jayant Madhavan and Alon Halevy of Google's crawling and indexing team said the company has begun an experiment in which its indexing software experimentally enters text in Web site forms to see what previously undiscovered pages may appear.
"In the past few months, we have been exploring some HTML forms to try to discover new Web pages and URLs that we otherwise couldn't find and index for users who search on Google," they wrote. "This experiment is part of Google's broader effort to increase its coverage of the Web. In fact, HTML forms have long been thought to be the gateway to large volumes of data beyond the normal scope of search engines."
The new Google indexing practice involves only "high quality" Web sites and doesn't run on sites with "robots.txt" files or other standard mechanisms of warding off indexing software.
To decide what words to "type" into the forms, the indexing software samples from among words on the Web page with the form, Google said.
The technology looks related to a company called Transformic that Google acquired, according to a blog post by Anand Rajaraman, who was involved with the technology earlier in his career, while working for Halevy.
Yahoo has also begun indexing the Web with its third-generation software, Slurp 3.0.
"With everything now in place, the rollout has officially begun," Sharad Verma and Yoram Arnon said in a blog post this week.
Unlike Google, Yahoo didn't detail what's new with its indexing software.
