Multi-Decadal Record of Ice Dynamics on Daugaard Jensen Gletscher, East Greenland, from Satellite Imagery and Terrestrial Measurements

The history of ice velocity and calving front position of Daugaard Jensen Gletscher, a large outlet glacier in East Greenland, is reconstructed from field measurements, aerial photography and satellite imagery for the period 1950-2001. The calving terminus of the glacier has remained in approximately the same position over the past similar to 50 years. There is no evidence of a change in ice motion between 1968 and 2001, based on a comparison of velocities derived from terrestrial surveying and feature tracking using sequential satellite images. Estimates of flux near the entrance to the fjord vs snow accumulation in the interior catchment show that Daugaard Jensen Gletscher has a small negative mass balance. This result is consistent with other mass-balance estimates for the inland region of the glacier.

Lessons from Ellen: A Case Study Investigation of Comprehension Strategy Instruction in Action

In the past ten years, reading comprehension instruction has received significant attention from educational researchers. Drawing on studies from cognitive psychology, reader response theory, and language arts research, current best practice in reading comprehension instruction is characterized by a strategies approach in which students are taught to think like proficient readers who visualize, infer, activate schema, question, and summarize as they read. Studies investigating the impact of comprehension strategy instruction on student achievement in reading suggest that when implemented consistently the intervention has a positive effect on achievement. Research also shows, however, that few teachers embrace this approach to reading instruction despite its effectiveness, even when the conditions for substantive professional development (i.e. prolonged engagement, support, resources, time) are present. The interpretive case study reported in this dissertation examined the year-long experience of one fourth grade teacher, Ellen, as she leanled about comprehension strategy instruction and attempted to integrate the approach in her reading program. The goal of the study was to extend current understanding of the factors that support or inhibit an individual teacher's instructional decision making. The research explored how Ellen's academic preparation, beliefs about reading comprehension instruction, and attitudes toward teacher-student interaction influenced her efforts to employ comprehension strategy instruction. Qualitative methods were the basis of this study's research design. The primary methods for collecting data included pre- and post-interviews, field notes from classroom observations and staff development sessions, infonnal interviews, e-mail correspondence, and artifacts such as reading assignments, professional writing, school newsletters, and photographs of the classroom. Transcripts from interviews, as well as field notes, e-mail, and artifacts, were analyzed according to grounded theory's constant-comparative method. The results of the study suggest that three factors were pivotal in Ellen's successful implementation of reading strategy instruction: Pedagogical beliefs, classroom relationships, and professional community. Research on instructional change generally focuses on issues of time, resources, feedback, and follow-through. The research reported here recognizes the importance of these components, but expands contemporary thinking by showing how, in Ellen's case, a teacher's existing theories, her relationship with her students, and her professional interaction with peers impact instructional decisions.