Ulmer, Gilbert2020-09-012020-09-011939-05-31https://hdl.handle.net/1808/30714Dissertation (Ph.D.)--University of Kansas, Education, 1939.This item is protected by copyright and unless otherwise specified the copyright of this thesis/dissertation is held by the author.EducationTeaching geometry to cultivate reflective thinking: An experimental study with 1239 high school studentsDissertationopenAccess