This study examines 11 interdisciplinary teams involving 30 teachers and 542 students in New York and California. The teams represented an array of approaches to interdisciplinary curricula, ranging from simple correlation to major reconstrual of the contributing disciplines. Teams that engaged in the most reconstrual of traditional content also tended to use instructional approaches that emphasized cognitively engaging instruction, including an emphasis on envisionment-building activities and extended discussion of significant ideas, but individual members of teaching teams still varied considerably in teaching style. The study concludes that interdisciplinary coursework is neither a problem nor a solution in efforts to increase student achievement; rather, it involves a number of tradeoffs that need to be considered at the school site. (Contains 7 tables.)