Factor structure and invariance of the POMS Mood State Questionnaire in Spanish.

The purpose of this study was to examine the extent to which the Spanish POMS assesses the same factors as the original form of the questionnaire. We started from a version with 63 items, representing seven conceptual dimensions. This version was administered to a sample of 364 adult athletes. In the whole sample, exploratory factor analytic findings suggested a more parsimonious measurement model, with 44 items and 6 first-order factors. Then the data from said sample were randomly divided into two sets, each containing about 50% of the subjects. The fit of the first sample set (n = 166) to the proposed model was adequate. Four of the main goodness-of-fit indices exhibited the following values: CFI = .95, NNFI = .95, SRMR = .083, and RMSEA = .064. We tested the same model in the second data set (n = 198), in which the fit was also acceptable, with values of .95, .94, .088, and .066 for CFI, NNFI, SRMR, and RMSEA, respectively. In addition, we used multi-group confirmatory factor analysis to provide evidence on the invariance of the model.