Abstract
An aptitude test was carried out on 265 junior high school students. The obtained data were analyzed by means of principal component analysis (PCA) and principal factor analysis (PFA) to explore the number and rough sketch of factors and then by mean of LISREL and its sensitivity analysis to investigate the structure of the test more precisely. It was found that the test was composed of three factors, i. e., the factors of coding and searching ability, symbolic processing ability and logical thinking ability, and that those results were not unstable for small changes of the data. It was also found that LISREL and its sensitivity analysis were useful for the analysis of this kind of data.
