Previous work has identified four areas of difficulty that students seem to have with the topic of similarity: (1) understanding the definition of similarity; (2) proportional reasoning; (3) dimensional growth relationships; and (4) correspondences in right triangle similarity. This paper reports the results of an investigation into high school…

Provided is an analysis of Turtle Geometry using van Hiele levels of development and understanding. The author also relates a language use framework, suggested by the work of Fry (1982), to the language activities of Turtle Geometry. Research supporting the analysis is discussed. (RH)

The aim of this study was to gain a better understanding of the difficulties met by adults with lower levels of education on reading perspective drawings. Subjects were asked to describe verbally two perspective drawings of objects, then choose objects with defined spatial properties. Results indicated that success was an "all or…

Secondary geometry students were tested for van Hiele level of thinking, geometry knowledge and achievement, and proof-writing achievement. Proof-writing achievement correlated significantly with van Hiele level entering geometry knowledge and geometry achievement. The predictive validity of the van Hiele model was supported. (Author/DC)

Presented is an alternative method for analyzing the van Hiele level of students' geometrical reasoning. The accuracy of students' answers may afford a description of acquisition and/or expertise for each of the van Hiele levels simultaneously rather than the traditional assignment and evaluation of one level at a time. (JJK)

Describes the stages of a process of reflective thinking. Investigates how geometrical models can be used in learning and teaching mathematics in connection with the process. Identifies two models for children of age four to eight: constant path in the space of shapes and continuous path of varied polygonal shapes. (Author/YP)

Summarizes a reanalysis of the data from an investigation of a test designed to measure a learning sequence in geometry based on the work of van Hiele (1986). Discusses the test based on the Rasch model. (YP)

Some research indicates that students often think that their drawings of three dimensional objects can be done without ambiguity, and that properties of drawings are properties of the objects. This "knowing vs. seeing" conflict was studied in three French sixth grade classes. (PK)

Graphical representations of geometrical objects from high school textbooks are categorized according to the implicit conventions underlying their display. The fact that specific illustrations can lead to students' misconceptions about geometric objects is analyzed in relationship to the principle of parallel projection with implications for the…

This research was designed to investigate several primary questions in comparing the Logo floor turtle to the Logo screen turtle: (1) Do young children gain different geometric concepts from experiences with the floor turtle than they do with the screen turtle? (2) Do young children learn to use the four basic Logo commands more efficiently with…

The ability of tenth grade plane geometry students to structure concepts and relationships from a geometry unit on ratio, proportion and similarity was tested. Analysis of cognitive "maps" of the structural relationships possessed by twenty concrete and twenty formal subjects indicated that formal operational subjects structure subject…

The production and application of images based on fractal geometry are described. Discussed are fractal language groups, fractal image coding, and fractal dialects. Implications for these applications of geometry to mathematics education are suggested. (CW)

Responds to Crowley's and Wilson's articles on the reliability of the van Hiele Geometry Test. Discusses the issue of the difficulty of trying to maximize content validity while minimizing measurement error. (YP)

Provides an alternative analysis of the reliability associated with the van Hiele Geometry Test based on the assumption that the norm-referenced reliability coefficients provided by the developers were inappropriate. Discusses the agreement coefficient and the kappa coefficient. (YP)

Secondary school geometry students have been found to have misconceptions concerning parallel lines. Correctional teaching programs did not seem effective in changing these misconceptions. This research describes an attempt to use teaching strategies which take into account current learning theory and which encourages students to be actively…