Dating sites are only as good as their ability to make matches. And how they go about making those matches can be very different. Mike Norton, Ph.D., is a professor at the Harvard Business School who was on the scientific advisory board of OkCupid.

“They are all matching on obvious stuff, like age range," he says, "but they vary a good amount on how they consider other factors that might affect compatibility.”

Sound vague? It is, intentionally. Online dating companies keep their proprietary algorithms closely guarded. So it's difficult for academics to figure out which ones do best.

But here’s what we do know: Companies like eHarmony and use algorithms based on information you provide (eHarmony’s has a U.S. patent) similar to the way Amazon and Spotify use algorithms to make product recommendations for consumers. In a 2013 article in The New York Times, eHarmony’s senior research scientist at the time, Gian C. Gonzaga, said that the company focused on factors such as the degree of sexual and romantic passion, the level of extroversion, and the importance of spirituality in making matches.

OkCupid, which was founded by four Harvard math majors, uses its own questions and those generated by members to make compatible matches based on how much users have in common. The questions are often quirky and can be oddly revealing, like “Do you often find yourself wanting to chuck it all and go live on a sailboat?”

Location-based apps like Bumble, Grindr, and Tinder use a smartphone’s GPS to find potential mates in a specific radius.

The bottom line. Don’t try to game the system. Instead, choose a site or an app based on the approach that makes the most sense to you. And always answer questionnaires honestly.

Editor's Note: This article also appeared in the February 2017 issue of Consumer Reports magazine.