In an ideal world, scientific evidence would guide social policy. But this is not an ideal world and often no available evidence speaks to the effectiveness of a proposed program or even an existing one. In fact, high-quality research evidence is sometimes available, but it is ignored for one reason or another. Or there is evidence of program effectiveness but the program is applied outside the range or scope of the actual research findings-the pharmaceutical analogy would be taking a drug that effectively reduces high blood pressure and using it to treat acne. In the end, when it comes to applying research to social policy and programs, the world we live in is neither ideal nor simple.