Abstract
Purpose: The psychometric properties of the Self-Motivation Inventory for children (SMI-C) were established using tests of factorial validity, factorial invariance, latent mean structure, and predictive validity. Methods: Adolescent girls from two cohorts (N = 955 and 1797) completed the SMI-C and measures of physical activity, team sport involvement, cardiorespiratory endurance, and body fatness in the 8th grade; participants in cohort 2 (N = 1,658) also completed the measures 1 yr later in the 9th grade. The data were analyzed with exploratory and confirmatory (CFA) factor analysis and structural equation modeling (SEM). Results: The 20-item SMI-C was best represented by a single substantive factor, but there were method effects among the negatively worded items. CFA indicated that a single-factor model fit the nine positively worded items and exhibited strong evidence of cross-validity and factorial invariance between races and across 1 yr; there were no differences in latent means between black and white girls. SEM indicated that the nine-item SMI-C had direct effects on moderate (γ11 = 0.16) and vigorous (γ21 = 0.22) physical activity and team sport involvement (γ31 = 0.29); the effects were invariant between black and white girls, independent of cardiorespiratory endurance and body fatness, and consistent across a 1-yr period. Conclusion: The positively worded nine-item version of the SMI-C can be used in cross-sectional, prospective cohort, and intervention studies that examine self-motivation as a putative moderator or mediator of physical activity among black and white adolescent girls.
Original language | English (US) |
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Pages (from-to) | 128-136 |
Number of pages | 9 |
Journal | Medicine and Science in Sports and Exercise |
Volume | 35 |
Issue number | 1 |
DOIs | |
State | Published - Jan 1 2003 |
Externally published | Yes |
Keywords
- Factor analysis
- Invariance
- Latent means
- Structural equation modeling
ASJC Scopus subject areas
- Orthopedics and Sports Medicine
- Physical Therapy, Sports Therapy and Rehabilitation