A Case Study of the Enactment of Proof Tasks in High School Geometry

Document Type

Conference Proceeding

Publication Date



proof, geometry, high school, teaching


This paper describes how a Midwestern geometry teacher enacted proof tasks with respect to levels of cognitive demands. Data were collected via teacher interviews, observation protocol, audio, and video recording of the enacted lessons and teacher artifacts. The results suggest that the guidance offered during whole class discussion often reduced the level of cognitive demand of potentially richer tasks. Furthermore, whenever the teacher talked less and allowed students to work independently or in groups, the enacted proof tasksgenerallymaintained higher-levels of cognitive demand.

Citation / Publisher Attribution

Proceedings of the Eight Congress of European Research in Mathematics Education (CERME 8)