The student-centered learning practices associated with constructivism could benefit from the increased class time that block scheduling offers. But, Mr. Hackmann observes, too often block scheduling is adopted as an end in itself, not as a tool to facilitate a specific pedagogical approach. THROUGHOUT much of the 20th century, classroom instructional practices tended to follow behaviorist learning theory, which regards teaching as a highly diagnostic and prescriptive process. The behaviorist approach typically advocates the presentation of curriculum content in small increments followed immediately by student practice. Behaviorism continues to play a significant role in today's classrooms, where many teachers rely primarily on direct instruction methods.1 In the past few decades, a growing body of research on cognitive processing has made inroads into classroom practices. Whereas behaviorism primarily focuses on the teacher's role as transmitter of knowledge, a different view of learning has emerged - constructivism - that emphasizes the student's role in the learning process. Building upon the work of Jean Piaget, Lev Vygotsky, and others, constructivist theory is based on the premise that individuals must be socially engaged in learning - actively creating knowledge from their existing knowledge base, beliefs, and personal experiences.2 Constructivists advocate learners' participation in context-bound, real-world problem solving and call upon students to engage in metacognition. Although constructivism appears to be attracting a growing following, it has not been readily embraced at the secondary school level. Arguably, constructivist practices may be implemented more easily in self-contained elementary classrooms or through the interdisciplinary teaming approach commonly used in middle schools. High schools tend to be departmentalized and more concerned with curriculum, and secondary teachers may be less willing to employ methods perceived as reducing the emphasis on content. An additional factor limiting attention to the constructivist movement at the secondary level could be the involvement of many faculties in another restructuring initiative - block scheduling. Much of the recent literature on high school education has addressed alternative scheduling, which may have overshadowed other educational trends. In the 1980s and 1990s, national task forces denounced the excessive rigidity of the traditional high school schedule - uniform 45- to 55- minute periods - and its stifling effect on classroom practices.3 In response, many faculties created block models that divide the instructional day into 80- to 110-minute class sessions, roughly double the length of traditional daily-period classes. Block scheduling has become established practice in high schools, but many educators are unable to explain why it is superior to traditional daily-period formats and what results it is intended to produce. Currently, there is no solid theoretical foundation for block scheduling, and there also is limited research documenting its effectiveness in improving student achievement.4 Many teachers have struggled to make effective use of the longer time blocks because they lack a conceptual understanding of the purpose for these extended time frames and of how they may facilitate learning. Constructivism and block scheduling appear to have occurred in parallel, yet independent, movements. However, there are many points of convergence between these two concepts. Here I present the commonalities between the two movements and demonstrate that block scheduling should logically be considered as a vehicle to promote constructivist practices. Constructivist Dialogue at the Secondary School Level In contrast to the well-developed teaching models based on behaviorism, constructivism is an emerging theory that is currently descriptive, not prescriptive, in nature.5 To promote greater comprehension and mastery of content, constructivists emphasize depth of understanding rather than a superficial treatment of subject matter. …