Study about the dimensionality of the Human Figure Drawing test

This work assessed the adjustment of Rasch model concerning the one-dimensionalityof the Human Figure Drawing Test. The participants were 1.207 students aged from 5 to 10 years old, of both genders. Considering that residuals may be enough to violate the items intrinsic one-dimensionality, the analysis of residuals principal component was used to assess the possible violation. Items with higher factorial load related to the positive and negative dimension of the first factor were selected. These items were re-analyzed through Rasch model within each group of data, and then the positive and negative factors were correlated. The result suggested the existence of more than one dimension, opposing to the use of a total score for diagnosis. The study about the measure disturbances at the examinees level showed that the main problem is related to the presence or absence of drawing details that are incompatibles to the figure’s global characteristics. Keywords: Rasch model; unidimensionality; Human Figure Drawing test.