Abstract: | Using a random sample of 389 grade 11 science students, the factor structure of the Longeot test (a measure of logical thinking) is investigated and some psychometric properties of the test items are determined. Varimax rotation on six principal component factors resulted in a simple structure. An attempt is made to interpret the obtained orthogonal factors. Implications of the findings on the “unity hypothesis” of the Piagetian construct of logical thinking and, consequently, on grade 11 science education are discussed. |