This volume of New Directions for Teaching and Learning increases our knowledge and understanding of the causes and consequences of disciplinary differences in the patterns of teaching and learning, in the instructional strategies to increase teaching effectiveness, in the culture and environment in which teaching takes place, and in faculty and students' attitudes, goals, beliefs, values, philosophies, and orientations toward instruction. Despite their practical and pervasive influence, disciplinary differences have been subjected to relatively little systematic study, especially in their effect on the quality of teaching and learning in higher education. This volume both provides new summaries of important studies on disciplinary differences and points out promising directions for further research. This is the 64th issue of the quarterly journal New Directions for Teaching and Learning.