Microsoft is so confident that its search engine Bing outperforms Google that is has created the Bing It On Challenge. But an academic study released earlier this year suggests that the best engine for you depends on the terms you're searching.

The marketing campaign (tag line: “Break The Google Habit”) was announced Thursday on the Microsoft blog, and it is modeled on the 1980s Pepsi Challenge.

Like the Pepsi Challenge, this challenge pits two market leaders in a blind, head-to-head test. Then it was Pepsi and Coke, now it's Bing and Google.

You can go to a special site to conduct five searches and get two blind lists of results. You rate each list for how it satisfied your search. Microsoft is wagering that a lot of Google users will be surprised to find out they like Bing results best.

When I took the challenge, Google won 3-1 with one draw.

I half-suspect that I picked Google's results because I habitually use Google, and its results somehow feel more familiar to me when they are presented alongside Bing results.

More comprehensive tests done by Microsoft, results of which were announced yesterday on the Bing blog, found that people preferred Bing results over Google by a margin of two-to-one in a blind test.

But recent research indicates that I preferred Google results more because of the actual search terms I used than any other factor. 

The study, by Indian researchers and published in January in the journal International Journal on Computer Science and Engineering suggests Bing and Google have complementary strengths based on search terms themselves.

For example, I used simple and short terms: Dave Copeland, Boston restaurants, social media in the classroom.

The study by Tauqeer Ahmad Usmani of Kumaun University, Durgesh Pant of Uttarakhand Open University and Dr. Ashutosh Kumar Bhatt of the Birla Institute of Applied Science, found that Google outperforms Bing on simple one-word queries. Bing generally delivered more precise results for simple, multi-word queries and complex multi-word queries.

Google Remains More Relative

In addition to measuring the precision of simple one-word, simple multi-word and complex multi-word search queries in both Google and Bing, the researchers measured the relative recall of each -- that is, how many of the sites returned were relevant.

In all three categories of search terms, Google returned more-relative results than Bing.

That means that in simple multi-word and complex multi-word queries, Bing may give the site you’re looking for as a top result, but Google will more often give a wider range of relevant results to your search.