OKCupid, the dating site owned by billionaire Barry Diller's IAC/InterActiveCorp, is the latest internet company to say it conducts psychological experiments on users.

OKCupid ran tests including analyzing the depth of conversations while users' pictures were removed for seven hours, co-founder Christian Rudder wrote in a blog post yesterday. The website also temporarily changed its profile-rating system and told people with low compatibility scores that they were better matches than the system had really determined, he wrote.

The disclosure follows an onslaught of complaints against Facebook, which disclosed in June that experiments were conducted in 2012 to influence what users saw on their news feeds without getting permission. While the move incited concern about privacy issues, Rudder said these types of tests are needed for websites to improve their products.

"Guess what, everybody: if you use the Internet, you're the subject of hundreds of experiments at any given time, on every site," Mr. Rudder wrote. "That's how websites work."

Rudder's post, titled "We Experiment on Human Beings!," said the testing revealed consumer behavior, such as showing that a profile's text is less than 10 percent of what people consider when rating profiles -- it's all about the picture. In the experiment where New York-based OKCupid displayed different compatibility scores than what the algorithm measured, he said the users were notified of the correct match score after the test.

Facebook's temporary influencing of what almost 700,000 readers saw on their news feeds in January 2012 prompted a digital-privacy group to file a complaint with the U.S. Federal Trade Commission.

~ Bloomberg News ~