[pessimizer]

Discriminate. If you have five candidates, all qualified, with marginal differences, take the one that has been historically discriminated against.

That is the only way to build a culture (industry-wide) where there is a diverse group of people making hiring decisions. Once that happens, diverse bigotries will tend to cancel each other out, and the lack of a visible glass ceiling in the profession will encourage more people to try to join it from discriminated against groups.

Marginal discrimination by feel and intuition is mostly voodoo anyway. Thinking Person X is the best person for the job because he worked on a project at Company Y that you thought was interesting isn't necessarily picking the best person for the job (unless the project is directly applicable to what you're hiring them for), but it is necessarily compounding any prejudicial hiring practices from Company Y that may or may not exist there. In addition, at the margins is when people are chosen because they went to the same school as you, or they share your hobbies.

Have a qualification line, and above that line, pick the most historically disadvantaged. If you're still not getting any diversity, examine your qualification line (have I only considered people who went to private universities?) or market your interest, as this blog does well:)