A three-part study of social studies curricula in four Wisconsin high schools revealed how teachers use the ways they present course content to maintain discipline and control in the classroom. Called "defensive teaching" by the author, the methods involve simplifying the content and reducing demands made on students. The three parts of the research included an intensive ethnographic analysis of the presentation of economics information in one high school's social studies classes; the extension of this analysis to three other schools; and a survey of student attitudes and employment outside school and of their effects on student school work. Analyzed in terms of the concept of school knowledge and the school's role in society, the study data showed how teachers use the forms of knowledge--namely, teaching techniques involving the fragmentation, mystification, omission, or simplification of economics knowledge--to control the knowledge and thereby control students. These "defensive" techniques were used by teachers from all the political perspectives and teaching philosophies encountered, working in classes with all variations in student ability. The author concludes that it is teachers' accommodation to the school priorities of control and efficiency that leads to the limiting of student access to human knowledge. (Author/RW)