Google began running a live test last year that lets people re-rank and remove search engine results and comment on them, but remains undecided about rolling out the changes for everybody.
The test, presented to a random portion of users, adds buttons next to result links to move them up and down, remove them from view and append comments to them.
Implementing these features permanently would be a major step for Google in giving more participation to its users in influencing the process of ranking and evaluating search results.
"It's a really fun experiment. I can't say for sure whether it will go live for everybody because we're always running a ton of experiments. Only some of those, the ones that are being very successful, are launched live for everybody," said Google software engineer Matt Cutts.
Google has presented people with different variations of the experiment, which the company first publicly detailed about two weeks ago in an official blog posting.
For example, in one version of the test, people can only remove results, while in another they can append comments that only they can see, Cutts said.
One challenge is how to apply the collected feedback in a scalable and useful way, but what's clear is that the data offers interesting insights to Google for search quality purposes. "Personally, I'm very excited by it and I hope that it does work out," he said.
Some Google critics complain that the company's search engine remains too closed to user participation, ignoring a basic Web 2.0 principle and favoring automated processes and mathematical algorithms.
However, Cutts takes issue with this argument. "A lot of times people think about Google as being nothing but algorithms and computers operating around the clock," he said. "But if you think about [Google's proprietary ranking system] PageRank, the way we judge how reputable a particular page is boils down to human judgments and actions in the sense that it depends on who is linking to whom on the web."
Still, some in the search field maintain that Google's reticence to give end-users more participation could end up harming it. Competitors like Jason Calacanis' Mahalo, Yahoo's Delicious social bookmarking service and Jimmy Wales' Wikia Search are examples of search engines that focus on users' contributions for their operation.
Wikia Search lets anyone add, delete and rate search results, as well as edit the content of a search result URL by modifying its headline and description. Changes appear immediately without going through an approval process. Following the wiki philosophy, Wales believes that the Wikia Search community will police itself and that a collective wisdom will prevail.
Google does offer some customisation and personalisation options to users with a Google account. For example, account holders can maintain a log of their search and browsing activity via a service called Web History, as well as bookmark and annotate site links with a service called Notebook.
While Google ponders implementing the test's feedback features to all its users, it is taking definitive steps to extend its search technology beyond analysis of text by understanding multimedia characteristics in photos, videos and audio, Cutts said.
For example, Google's Image search engine can now be told to filter results and return only photos of people because it can recognize whether a face dominates the image, Cutts said. In video search, Google has started creating transcriptions of speech, so that people can search for what is said on a clip. "We're not just relying on metadata," Cutts said.
"We have people at Google who are voice-recognition experts and image-recognition experts and video-recognition experts, so it's really quite exciting to think about the future of search in terms of understanding more about voice and video and images," he added.
Cutts, who is very well-known in search circles and whose blog is required reading for search specialists everywhere, also challenges the charge that Google doesn't employ semantic search technology, which seeks to understand the meaning of web pages as opposed to analyzing links and keywords.
"Many people have a misconception that Google only searches for exactly the words that you type," he said. "We try to be a little more helpful. We search for different [word] stems, so for 'run' we might search 'running' and even for synonyms, so if a page has the word 'jogging' that can help us quite a bit even though your query was 'running' or 'run.' So we actually do quite a bit of semantic searching to try to help the user out."
Asked whether Google is worried about being locked out of popular social-networking sites like Facebook that limit search-engine crawling, Cutts said that Google is happy that the overall trend over the past 10 years has been toward openness.
"The high order bit for us is we don't want to index content if the site owner doesn't want us to," he said. "That said, over time, the vast majority of sites have realized that it can be very helpful to have pages within the search results. Although there are some walled gardens, a lot of these places open up over time if they see the benefit and rewards in showing up well in different search engines."