The content of effective service-learning programs has not been the focus of experimental research; most, if not all, has been correlational or qualitative. However, there are data available that suggest particular program attributes of which program designers should be aware. For instance, Conrad and Hedin (1982), in an evaluation of 27 experiential education programs, found that the presence of seminars that occur at least once per week was the strongest variable predicting student positive citizenship. Also, engaging youth in the formation of service-learning programs has been suggested as an important program characteristic. Such interactive classroom time allows for reflection and makes for an explicit connection between the service and the learning (Katula, 2000). Other factors that have been found to be effective components of service-learning programs include the length of the program and the number of experiences (i.e., program intensity; Conrad & Hedin, 1982). Providing opportunities for interesting activities in which adolescents feel appreciated for their work and they can see the impact that they have on their communities may help to make the experience a positive one for youth. Research findings also suggest that students should be involved in the formation of the programs. In other words, youth should be given a voice in deciding the types of activities in which to participate and the curriculum in school (Civic Liberty Project, 1999; Garvey, McIntyre-Craig & Myers, 2000; Katula, 2000; Morgan & Streb, 2000). Garvey and colleagues (2000) make several suggestions for how to give youth a voice. They suggest allowing adolescents to assess their community's needs for programs, making sure to engage adolescents in discussion during class time, sharing program planning responsibilities, letting youth help with determining the budget and funds needed for the program, allowing youth to apply what they have learned in the classroom to the implementation and eventual evaluation of the program, and celebrating the impact that they and the program have had on the community.