This is an electronic version of a white-paper presented to the NCTM Standards 2000 Electronic Format Group in June 1998. In order to access the interactive diagrams embedded in this document, you'll need a Java-capable web browser. In our experience, at the time of writing, Microsoft Internet Explorer or Netscape Navigator Version 4 (for PC or Macintosh) work well; Version 3 works less well; and prior versions work not at all. Your mileage may vary. A print edition of this paper may be available at a later date from the conference publication of the NCTM EFG.
This material is based in part upon work supported by the National Science Foundation under awards numbered III-9400091 and DMI-9623018. Any opinions, findings, and conclusions or recommendations expressed in this paper are those of the authors and do not necessarily reflect the views of the National Science Foundation.
You may also download a copy of this paper in Microsoft Word 6 format (.zip or .hqx archive).