Consumers can find more of what they want on the Web, but that may not always be such a good thing. New research about online dating sites shows that users presented with too many choices experience "cognitive overload" and make poorer decisions as a result. The findings could have implications for other kinds of websites, although new technologies and approaches could help address the problem, researchers suggest.

Dating sites are big business. According to a survey conducted in 2006 by the Pew Center for Internet and American Life, over 37% of all single Web users have tried them. Dating sites frequently resemble e-commerce sites such as Amazon.com; users enter search criteria such as height, appearance, and religion and are presented with a set of matches.

Pai-Lu Wu from Cheng Shiu University and Wen-Bin Chiou from the National Sun Yat-Sen University in Taiwan performed an experiment that involved giving online date-seekers varying numbers of search results to their queries on dating sites. Their study, published last month in the journal Cyberpsychology and Behavior, shows that having more search results leads to a less careful partner choice.

Chiou calls this a "double-edged sword," since people desire a wider selection, but then devote less time to evaluating each prospect. Wu and Chiou conclude that "more search options lead to less selective processing by reducing users' cognitive resources, distracting them with irrelevant information, and reducing their ability to screen out inferior options." In other words, when faced with cognitive overload, date-seekers evaluated as many matches as possible, even ones that weren't a good fit, and they were less able to distinguish a good option from a bad one.

Michael Norton, an assistant professor at Harvard Business School, coauthored a study published in the Journal of Interactive Marketing last year that suggests that this kind of cognitive overload is common on dating sites. His study found that the average date-seeker typically spends nearly 12 hours a week searching online and emailing for a payoff of less than two hours of offline dating. Norton says that date seekers "evaluate each person only superficially, never investing the time and energy to explore whether a match might work." Having too many options raises our expectations of potential matches too high, leading to an "often fruitless search for an ideal person who may not exist." Incessant browsing for Mr. or Ms. Right may be exactly the wrong decision, Norton says.