Abstract:

One of the aims of the current study is to specify the model providing the best fit to the data among the exploratory, the bifactor exploratory and the confirmatory structural equation models. The study compares the three models based on the model data fit statistics and item parameter estimations (factor loadings, cross-loadings, factor correlations) provided by the models. The second aim of the study is to examine correlations among the factor scores, the academic achievement and the goal orientations to provide criterion validity for the person parameter estimations of the best-fitting model. The Academic Motivation Scale was conducted on 1,858 junior and senior students. The three measurement models were compared based on the model data fit and parameter estimations. All estimations were done on the Mplus 6.0 statistical program using the Maximum Likelihood method. It was found that the bifactor exploratory structural equation model provided only trivial improvement on the model data fit relative to the exploratory structural equation model. However, the results of the study revealed that including a general factor in the model achieved a decrease in item cross-loadings. In addition, items could lie along the relative autonomy continuum in a consistent way with the Self-Determination Theory according to their general factor loadings estimated by the bifactor model. The model data fit statistics, parameter estimations and correlation coefficients indicated that the bifactor exploratory structural equation better fit to data than the other two models both theoretically and statistically.

Keywords: