Considering that there are now 4,000 to 5,000 tests for heritable conditions, the question of how good is any test if it doesn't lead to actionable results is on the mind of a lot of people in the consumer genetic testing industry. Scripps' Eric Topol is conducting an experiment to see if taking a test (in this case, they're using Navigenics) will spur people to actually improve their lifestyles. Most experts still urge caution. If you're not taking the test under genetic counseling supervision, you might as well skip it, says one. Michael Watson, executive director of the American College of Medical Genetics, says a test should at least give you "the frequency of positive results and the number of people who test positive but never get the disease," says this article in Forbes. "These are very general concepts," Watson says, "but if someone can't tell you the answer to those, they're probably not ready for prime time."