I don’t know whether the Implicit Association Test (IAT) is accurate or not, but it’s a great conversation opener. In diversity and anti-racism workshops, participants often deny having any prejudice at all. Inviting them to take a couple of these mini-tests, without sharing the scores with anyone else, might be an effective way to encourage them to address ways that prejudice affects workplaces, and what people can do to minimize it.

Welcome to the disturbing world of implicit bias, where people's preferences for racial, ethnic, and other groups lie outside their awareness and often clash with their professed beliefs about those groups. In the past 15 years, most social psychologists have come to agree that implicit biases, also known as unconscious attitudes, play an often-unnoticed role in our lives. Researchers study implicit biases using any of several techniques, such as tracking participants' feelings and behaviors after subliminally showing them pictures of black or old people.
However, one measure—the Implicit Association Test, or IAT—has proved especially popular.

From The Bias Finders: Science News Online, April 22, 2006.

 You can take the IAT here.