Summer Edition 1994 © 1994 TABLE OF CONTENTS

A Diagnostic Analysis of a Proportional Reasoning Test Item: An Introduction to the Properties of a Semi-Dense Item William M. Bart, Thomas Post Merlyn Behr and Richard Lesh

The Use of Taught and Invented Methods of Subtraction A.D. Perry and Kaye Stacey

Designing and Evaluating Effective Games for Teaching Science and Mathematics: An Illustration from Coordinate Geometry Steven Pulos and Cary Sneider

What Writing Reveals in Mathematics Bob M. Drake and Linda B. Amspaugh