Use of change scores in redundancy analyses of multivariate psychological inventories

Both canonical and multiple-regression redundancy analyses were computed on the 20 separate subscale change-scores for the Eight State Questionnaire (8SQ) and the Differential Emotions Scale (DES-IV), using a sample of 212 undergraduate students. In comparing the measurement overlap of the two measures, it was important, since state-change dimensions were of interest, that across- occasions difference scores be used rather than single-occasion absolute scores. Viability of this approach was demonstrated and only minor redundancy was evident for the 8SQ and DES-IV instruments. On the present evidence, it appears that both inventories are tapping essentially discrete psychological variance (allowing for trait contamination) and that probably neither instrument alone is an adequate measure of the total ‘mood-state sphere’.