Adults are prone to treating percents, one representational format of rational numbers, as novel cases of natural number. This suggests that percent values are not differentiated from natural numbers; a conceptual shift from the natural numbers to the rational numbers has not yet occurred. This is most surprising, considering people are inundated…

Reports on a study to determine the development of children's understanding of seven properties of the arithmetic mean and to assess the effects of material used in the testing and the medium of presentation. Some differences were found in children's reasoning. No significant differences were found for materials or medium of presentation. (PK)

Many students can calculate the arithmetic mean but do not understand the concept. The article presents four activities designed to help elementary and middle school students develop this concept. The activities presented assume previous exposure to the computational algorithm for the arithmetic mean. (Author/EK)

A two-year investigation into the development of computer-assisted instruction (CAI) for the improvement of undergraduate training in statistics was undertaken. The first year was largely devoted to designing PLANIT (Programming LANguage for Interactive Teaching) which reduces, or completely eliminates, the need an author of CAI lessons would…

Interviews with (n=21) fourth, sixth, and eighth graders, who were asked to construct their own notion of average and representativeness in open-ended problems, identified five basic constructions of average as mode, an algorithmic procedure, what is reasonable, midpoint, and a mathematical point of balance. (16 references) (MKR)

This volume of the 27th International Group for the Psychology of Mathematics Education Conference includes the following research reports: (1) The Affective Views of Primary School Children (Peter Grootenboer); (2) Theoretical Model of Analysis of Rate Problems in Algebra (Jose Guzman, Nadine Bednarz and Fernando Hitt); (3) Locating Fractions on…