Abstract
Diagrams are a form of communication that are particularly useful for conveying geometric
ideas. Children experience difficulty with diagram interpretation in geometry and also with
the interpretation of graphics in geography. The similarity of children's difficulties in
geometry and geography led to an examination of a model of levels of mastery of
representation (Liben & Downs, 1991) based on geography, to determine its applicability
for mathematics. Diagram interpretation was explored through observation of eight babies'
behaviour with a three-dimensional shape and a corresponding diagram, and interviews
with eight Grade 2 children and eight Grade 5 children. This study provides evidence of
differing levels of children's understanding of geometric diagrams. Although the results
support only two of the four levels of Liben and Downs' (1991) model, a refined five level
model is proposed. The results indicate that the interpretation of diagrams may be a
constraint to effective communication in geometry.
CARMEL DIEZMANN
THE USE OF GEOMETRIC DIAGRAMS IN THE PRIMARY SCHOOL