There are many articles that seek to illustrate the positive results that stem from active-learning techniques. Krain and Lantis
(2006) note a number of studies that show how active-learning approaches increase student comprehension (Jensen 1998), enhance student problem-solving skills (Bransford et al. 1989; Lieux 1996), and increase the retention rates (Stice 1987; Schacter 1996; Silberman 1996; Hertel and Millis 2002). They also aid students in understanding abstract concepts (Pace et al. 1990; Smith and Boyer 1996). Despite these claims, however, Raymond (2010) emphasizes a surprising lack of systematic empirical evidence. Several recent studies note that most claims are based on subjective impressions of the instructor or students (Shellman and Turan 2006; Powner and Allendoerfer 2008). There are many examples of anecdotal support for the effectiveness of active-learning techniques. These can take a variety of forms (Newmann and Twigg 2000). Many are done through debriefing sessions. Chasek (2005) invites students to sit in a circle and discuss the challenges of negotiation and of organizational structural reform following a Security Council simulation. Students “admitted that the simulation gave them an entirely new perspective on the problems encountered in changing the membership and modalities of the Security Council” (Chasek 2005). Switky (2004) recommends letting students work in small groups to summarize the exercise's important lessons and then share these with the whole class. Lessons that emerge are often comparisons of how the simulation and real life differ. Zeff (2003) notes that outspoken students can dominate oral debriefings and recommends a written component. In the student surveys of her European Council simulation, students state that “they are more actively engaged in learning the class material because they have to defend their countries’ positions to the other participants” and that the simulation “helped them to appreciate the complexities of decision making in the EU [European Union]” (Zeff 2003).