caa a22 4500 467997217 CHVBK 20180323112600.0 cr unu---uuuuu 170328e19900601xx s 000 0 eng 10.1007/BF00305090 doi (NATIONALLICENCE)springer-10.1007/BF00305090 Overcoming visual obstacles with the aid of the Supposer [Elektronische Daten] [Michal Yerushalmy, Daniel Chazan] This paper presents research about the effect of intensive work with diagrams on high school students' use of diagrams in geometry. It identifies three obstacles, culled from previous research, which students must overcome when examining and interpreting diagrams: Diagrams are particular; common usage confuses certain standard diagrams with the classes of objects to which they belong; and a single diagram can be viewed and described in different ways. The paper outlines the resources of the Geometric Supposer, a set of microcomputer software tools which were designed to aid students in overcoming these obstacles. The bulk of the paper presents evidence from students' papers and classroom comments indicating that over the course of a year's work students using the Supposer became more facile in their use of diagrams and were able to overcome each of the three obstacles. Kluwer Academic Publishers, 1990 Yerushalmy Michal Center for Learning Technology, Education Development Center, 55 Chapel Street, 02160, Newton, MA, U.S.A. aut Chazan Daniel Center for Learning Technology, Education Development Center, 55 Chapel Street, 02160, Newton, MA, U.S.A. aut Educational Studies in Mathematics Kluwer Academic Publishers 21/3(1990-06-01), 199-219 0013-1954 21:3<199 1990 21 10649 https://doi.org/10.1007/BF00305090 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00305090 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Yerushalmy Michal Center for Learning Technology, Education Development Center, 55 Chapel Street, 02160, Newton, MA, U.S.A aut NATIONALLICENCE 700 1- Chazan Daniel Center for Learning Technology, Education Development Center, 55 Chapel Street, 02160, Newton, MA, U.S.A aut NATIONALLICENCE 773 0- Educational Studies in Mathematics Kluwer Academic Publishers 21/3(1990-06-01), 199-219 0013-1954 21:3<199 1990 21 10649 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer