A cognitive account of teachers' descriptive knowledge

This dissertation uses fine-grained cognitive methods to examine the descriptive knowledge of teachers. Central elements in this knowledge are descriptors, schemas that represent aspects of the classroom that teachers find familiar, such as "students are engaged." Besides helping to articulate what is perceived, because descriptors are connected to a range of knowledge elements they have another function: They index teachers' body of knowledge, helping to find and activate contextually relevant elements. An instance of knowledge activated by descriptors is pitfall knowledge ---used in negotiating problematic situations.;The data corpus that was analyzed in this investigation were audiotape recordings of teachers' collaborative lesson planning meetings. Each meeting was examined in fine detail, documenting descriptor use and investigating events in which descriptors helped activate relevant pitfall knowledge. This analysis informed the construction of a catalog that lists and describes descriptors for representing students' knowledge and engagement.;The constructed taxonomies were used in comparing the descriptive knowledge of two types of teachers. The first, learner-centered teachers, craft lessons to suit their students' needs and guide them in discussions where they make sense of ideas, while the second, traditional teachers, spend their time lecturing and engaging students in exercise sheets which leave little room for inquiry and reflection. A central hypothesis was that learner-centered teachers have a richer language for describing their students' knowledge and engagement, reflecting a richer knowledge base regarding student behavior, and that they use this knowledge more frequently than traditional teachers.;The comparison showed marked differences in the knowledge of these two types of teachers, differences which were significant in some cases. With respect to the richness in their vocabulary for representing students' knowledge, traditional teachers tended to focus on whether students did or did not understand a particular topic, while learner-centered teachers considered in addition the partial understandings students were developing. And with respect to richness in their vocabulary for representing students' engagement, while traditional teachers focused on whether students were engaged or not, learner-centered teachers focused on nuances of their engagement---whether their engagement was increasing or decreasing and whether they were frustrated, overwhelmed, or confused. Finally, there were also differences in frequency of use: Learner-centered teachers described their students' knowledge and engagement more often than traditional teachers.