As has been pointed out, ideological and social values play an important role in how historical contents are selected and taught in the schools. On the other hand, even historians' theories are based on the historiographical perspective each historian holds. Thus, the instructional implication of these aspects is that students' development of critical thinking should be an important goal of history instruction. For instance, it would be useful to promote students' comparisons of different versions of historical events (as suggested by Hahn, this volume). These types of activities could help students to develop a relativistic conception of historical knowledge ( Kuhn, Weinstock, & Flaton, this volume), may lead them to a better understanding of historical causal explanations, and may be useful for promoting the learning of some basic ideas about how historians build historical knowledge.
Narration plays an important role both in history and how history is taught in schools. Very often the way history is taught consists of offering the "story of the past." This could partly explain some of results. Do students and adult nonexperts in history generate intentional explanations partly because of this widespread conception of history as a "story of the past"? If instruction is oriented in a different way, would these subjects be able to generate different explanations? These are interesting questions opened to future research. Furthermore, by being intentional explanations based on personal agents -- the starting point in students' explanations -- the teacher could use them as a first step in helping students to develop more elaborated explanations.
On the other hand, another important issue from an instructional point of view is the complexity of students' historical explanations. Independent of students' causal explanations in history being more based on political and abstract factors or on personalized ones, it is essential to consider their complexity. In this respect, it is interesting to consider that most of the adolescent explanations do not take into account the political and foreign affairs context of the discovery of America. We think that to offer and emphasize that context should be an important goal of history instruction.
This research was supported by grant (PB91-0028-C03-03) from DGCYT, Spain, to the first author. This chapter was written during a sabbatical leave of the first author at LRDC, University of Pittsburgh (scholarship from Spanish Ministry of Education). We thank J. F. Voss and D. Resnick for his very valuable comments on a first draft of this chapter. Carmen Vizcarro and Iris Berent also provided useful suggestions. Saul Bitran gave us the first notice about the Mexican history textbooks case.