Investigated the structure of intra-individual mood (P-factors) for the presence of 2 dimensions of self-reported current mood—Positive and Negative Affect—found previously in interindividual R-factor analyses (A. Tellegen, 1980). 23 undergraduates completed a 60-item mood adjective checklist for 90 consecutive days. Quantitative comparisons of each S's 1st 2 rotated P-factors to the R-factor dimensions resulted in the identification of the 2 dimensions for 21 Ss, underscoring the congruence of the 2-dimensional structure identified within and across Ss. The belief that the idiographic study of individuals, rather than being antithetical to scientific psychology, can provide information of value and relevance to nomothetic description was basic to the investigation.(23 ref)(PsycINFO Database Record (c) 2016 APA, all rights reserved)