While service-learning, community service and volunteer programs have been a part of schools and colleges in the United States for decades and there have been a range of research and evaluation studies, there is a general lack of solid evidence on its effects. One of the major difficulties in evaluating or researching service learning programs is the lack of agreement on what is meant by the term and exactly what it is meant to accomplish. While some programs emphasize social growth, character development or civic responsibility, others attempt to study psychological development and effects of program.s on self-concept. Moral judgment studies have sought to evaluate the effects of service on moral and ego development and others have attempted to measure the effects of service on the broader community. Perhaps the most difficult arena has been in the area of intellectual, cognitive and academic effects. It has been difficult to design tight experiments to isolate the effects of service on specific academic achievements. A recent experimental study (Markus, Howard & King, 1993) of students in a university political science course provides some of the first strong evidence of the positive academic effects of service-learning.
Kraft, Richard J. and Krug, James, "Review of Research and Evaluation on Service Learning in Public and Higher Education" (1994). Higher Education. 108.