This technology report presents the main features of a free digital educational tool which aims to introduce middle school level students to the comprehension of the particulate nature of matter in the three states (i.e., solid, liquid, and gas) and during phase transitions. This digital tool is available and is freely accessible online. Its…

Spatial ability was defined by Lohman (1996) as the ability to create, maintain, retrieve, and change visual pictures. Linn and Peterson (1985) distinguished among spatial perception, mental rotation, and spatial visualization. Spatial perception is the determination of spatial connections with respect to the orientation of the learners' body;…

Many introductions to algebra in high school begin with teaching students to generalise linear numerical patterns. This article argues that this approach needs to be changed so that students encounter variables in the context of modelling visual patterns so that the variables have a meaning. The article presents sample classroom activities,…

When the author started his visualization session at Brampton by showing a still from Kate Mackrell's "Kaleidoscope," he was immediately struck by one student's description of a symmetry and reflection line that was quite at odds with what he was holding. Since he had seen the whole thing moving on a number of occasions, the author was hanging on…

Replicated a study to determine if a sex difference in spatial visualization ability exists among grade six students verging on adolescence and if instruction differentially affects boys/girls at this age. Although instruction significantly affected boys/girls in grades seven to eight, current results do not support the same interaction among…