now a growing literature on participatory research that may be helpful.

• NIH may wish to commission a review of the alternative mechanisms that programs have used to incorporate representatives of recipients in their decision making, including some evaluation of the success of those mechanisms.

1. The findings stated previously in the overall findings section apply specifically to communication campaigns: There are many such campaigns, and many address issues of diversity in their plans and their implementation; there is credible evidence for the overall positive effects of some of these programs; there is sometimes evidence available about differential trends with regard to target outcomes for different demographic groups, but there is little evidence available as to whether diversity strategies contribute to success, or as to which strategies are more and less effective.

2. Sophisticated public health communication programs pay close attention to the heterogeneity of their audiences, recognizing that their audiences are different with regard to the behaviors they are currently undertaking; the psychological, social, and structural factors that influence those behaviors; the channels through which they can be reached; and the types of message executions to which they will respond. They follow the lead of commercial marketers who “segment” the audience into more homogeneous groups, choosing to focus attention on only some segments, or addressing multiple segments with different communication strategies. Sometimes these segments correspond to the conventional diversity categories based on demographic characteristics. Sometimes there is much less correspondence. In these situations, relying on the conventional categories to segment the audience can be unproductive. Recently, some programs have used tailored approaches designed to customize interventions for individuals. In this case, the factors relevant to an individual can be used as the basis for messages.