Due to the character of the original source materials and the nature of batch digitization, quality control issues may be present in this document. Please report any quality issues you encounter to [email protected], referencing the URI of the item.Includes bibliographical references (leaves 49-54).Issued also on microfiche from Lange Micrographics.During the history of geometry people gradually acquired physical knowledge of space, and later consolidated it in a more abstract form of knowledge, geometry. In this thesis we describe a study performed on fifth grade students. The study describes how elementary school students used physical manipulations in conjunction with the digital interface of educational software for geometry. The blending of physical manipulations and digital interface helped the students to overcome the limits of the representation and interaction modalities of the digital interface. The addition of physical manipulations also helped them to consolidate their physical knowledge of the world and smooth the transition from the physical world to the abstract
