ASSESSING STUDENT UNDERSTANDING OF PLATE TECTONICS

A large-scale assessment of students in grades 6-10 on the topic of plate tectonics is being used to study student understanding of content ideas in Benchmarks for Science Literacy and the National Science Education Standards . In this study, assessment items are designed, rigorously evaluated, and piloted with students. The item evaluation procedure focuses on the alignment of test items to content standards and the comprehensibility of items to all students. The piloting format asks students to explain which answer choices they think are correct and incorrect, to circle words they don't understand, and to indicate when they think a diagram was helpful or if one is needed. Pilot testing is used in combination with one-on-one interviewing of a smaller number of students to provide for a deeper probing of student understanding that pilot testing does not allow.

Results will be presented that provide insights into student understanding and any misconceptions they hold after typical instruction, (i.e., instruction that is not explicitly aligned to the targeted content standards), appropriateness of terms, and age appropriateness of content ideas. For example, one set of results shows that the use of the term “bedrock” instead of the descriptive phrase “solid rock” affects student response to an item about plates. Only 15% responded “unsure” to answer choices for a version of an item using “solid rock” whereas 38% responded “unsure” to answer choices for the version (otherwise identical) using “bedrock.” When asked to define “bedrock,” 94% could not do so, indicating that students do not know what “bedrock” is following typical instruction, which has significant effects on how knowledge about plates can be assessed. Of students who thought they knew the meaning of “bedrock” and provided a definition, 36% revealed a misconception that bedrock is associated only with the ocean floor. Similar types of results on other content ideas will be presented. This work is funded by the National Science Foundation ESI 0352473