What makes someone a "97% match"?

Online Dating: The Science of Matchmaking

Once you’ve filled out a profile, online dating sites will provide a list of matches -- people they think you are compatible with. How do they decide who matches up with who?

Sometimes, the process is very simple. Each profile has a list of attributes or interests that members check off. The more matching attributes that two profiles have, the higher “match percentage” the site will assign to it. Some sites, like match.com, allow users to specify how important each attribute is. Each matching attribute is assigned a different weight depending on how important it is to the user. For example, if you prefer blondes, but really have nothing against brunettes and redheads, then you can rank that attribute as very low. If it’s very important to you that your date has a college degree, you can rank that very high. Then the site will match you with highly educated brunette sooner than a blonde who didn't finish high school.

Some sites use very complex personality surveys and mathematical algorithms to match partners. Online matchmaking site eharmony.com uses “29 key dimensions that help predict compatibility and the potential for relationship success.” Their system was developed by Dr. Neil Clark Warren, who studied thousands of marriages to develop his “predictive model of compatibility.”

Do such scientific methods work? Obviously, the dating sites claim they do. However, scientific personality tests completed with the guidance of a trained researcher do not have 100 percent accuracy (it’s closer to 75 percent). And when you’re sitting alone in your living room filling out a personality profile on a Web site, there is an even greater chance that the resulting matches will not be perfect. When you multiply the chance for inaccuracy by the number of users on a given dating site, complicated matching systems are probably not working much better than basic attribute-and-interest matching.

Fortunately, the main advantage of online dating is that it gives each user control over who they contact and with whom they subsequently communicate. It might take more work than relying on the site's matching system, but browsing through profiles yourself may ultimately be the best way to find the right person.

Specific facts and figures for online dating are hard to come by. For obvious reasons, each individual site tends to inflate membership numbers and success rates in its promotional materials. There are close to 100 million single adults in the United States alone. Of those, 40 million use online dating services [ref]. FriendFinder.com claims over 11 million members. Eharmony.com claims responsibility for more than 9,000 marriages.

On the other hand, there are those who think the online dating industry may have reached its saturation point. According to an article in the Christian Science Monitor, consumer spending on these sites declined slightly in the fourth quarter of 2004, indicating that growth for online dating sites may be stagnant.

While some of the numbers may be fuzzy, one thing is certain –- the use of online dating services continues in huge numbers. According to Online Media Daily, consumer spending on personals and dating sites rose by 8 percent in the first half of 2005, topping $245 million.

For more information on online dating and related topics, check out the links on the next page.