Google received the highest score in search engine quality in a test by uTest, while challenger Microsoft Bing received great accolades in usability and design and surprised people enough to make them switch to the new search engine, uTest said Sept. 14.

Software quality concern uTest farmed out a test of the Google, Google Caffeine, Bing and Yahoo search engines to more than 1,100 software quality testers from more than 50 countries in a classic example of crowdsourced peer review. The uTest report, which shows some intriguing data points to underscore the increasing competition between Google and Bing, is available online here. (PDF)

Looking at the four search services over the course of one week in August, the participants found 606 bugs and ranked the engines for search results accuracy, page load speed, real-time relevance and usability.

Google emerged as the leader in these categories, followed by Bing and Yahoo. Nearly 90 percent of all the respondents said Google was their favorite search engine in spite of the 130 bugs the testers found, 8 percent of which were said to require immediate attention by Google programmers.

However, in a sign of the powerful alternative to market leader Google that Bing is proving to be, 10 percent of the testers said they would make Bing their search engine of choice. This is stunning considering Bing logged a whopping 321 bugs, 14 percent of which were found to require speedy resolution by Bing engineers.

Perhaps this is due to the fact that more than 30 percent of the testers found that Bing pleasantly surprised them, according to uTest.

Moreover, uTest noted in its report: "Don't let the number of bugs fool you, Microsoft is onto to something big with Bing. As one of our testers remarked, 'Even though Google says there's no competition, my experience indicates there is definitely one now.'"

Seventy-one percent of the survey respondents chose search results accuracy as their most important criteria when choosing a search engine. With a score of 90 percent, Google led the way in accuracy, with most testers rating it as excellent or good. Google Caffeine followed closely with 83 percent. Yahoo and Bing trailed with 53 and 42 percent, respectively, uTest found.

Google Caffeine brought some interesting results in that the sandbox was launched only a few days after uTest triggered its survey of search engines. Only 22 percent of uTest participants tested Caffeine, finding it to be twice as fast as Google; 50 bugs were found.

Yahoo was easily found to have the fewest flaws, with only 70 reported. That might be small consolation for that fact that Nielsen has found that Yahoo is losing search engine market share to Bing. In its August U.S. search engine rankings, Nielsen said Yahoo's search share dropped 4.2 percent to 16 percent from July to August. Bing, however, grew from 9 percent share in July to 10.7 percent in August.

While Google's Caffeine is percolating, Bing is also demonstrating some heady innovation. At TechCrunch50 Sept. 14, Microsoft unveiled Bing Visual Search, which offers users a new way to search. Rather than typing in text and getting links, Visual Search lets users type in text and see images that lead to search results.