A company has come up with a new selection test and decides to try it out on some of its current workers before giving it to job applicants. A group of its current workers volunteered to take the test: 84 percent were male and 7 percent were over the age of 40. The scores on the test that each of the volunteers earned were correlated with the performance ratings each of the workers received in the company's annual performance review process. The sizable correlation between the two sets of scores led the company to conclude that the test is valid. What type of validity evidence has the company generated? Are there potential problems with the company's estimate of the validity of its test? Describe these potential problems.