Abstract

The longitudinal psychometric properties of SPPC were assessed using a sample of 157 schoolchildren across four time periods using structural equation modeling. The theoretically derived multidimensional structure of SPPC (Harter, 1985) and its associated reliabilities were found to be fairly consistent overtime. The stability of the factor structure, however, did vary across repeated administrations: the stability of the second-order self-perception factor was relatively low (0.629) between first and second administrations, increasing between times two and three (0.812), while reaching the highest point (0.941) across times three and four. This result could be attributable to either a growing familiarization with scale items, the response format, or natural respondent maturation. While the reason underlying temporal instability is uncertain, the results do suggest that caution should be exercised when interpreting SPPC scores particularly in intervention designs with comparatively long intervening periods. (C) 2003 Elsevier Ltd. All rights reserved.