Portuguese Physical Literacy Assessment Questionnaire (PPLA-Q) for adolescents (15-18 years) from grades 10-12: validity and reliability evidence of the Psychological and Social modules using Mokken Scale Analysis

Abstract Background Aims of this study were to assess construct validity (dimensionality, measurement invariance, convergent and discriminant validity) and reliability of the previously developed Psychological and Social modules of the Portuguese Physical Literacy Assessment – Questionnaire (PPLA-Q). Methods Mokken Scale Analysis was used in a final sample of 508 Portuguese adolescents (Mage= 16, SD = 1 years) studying in public schools in Lisbon. A retest subsample of 73 students, collected 15 days after baseline, was used to calculate Intraclass Correlation Coefficient (ICC). Results The 8 scales in the 2 modules can be interpreted as moderate to strong Mokken scales with H coefficient ranging from .47 to .66; 4 of these scales had an interpretable Invariant Item Ordering (HT>.30). Results suggest that all scales function similarly in male and female adolescents, except for the Physical Regulation scale which has shown evidence of a sex bias. All scales had good total score reliability (ρ > .80, ranging from .83 to .94); regarding test-retest reliability: 3 scales had good to excellent reliability (ICC95%CI ranging from .72 to .95), and 5 scales presented moderate to good reliability (ICC95%CI ranging from .51 to .85). Scales score correlated as theoretically expected, with low to moderate across domain correlations providing support of convergent and discriminant validity. Conclusions Evidence supports the construct validity and reliability of the psychological and social modules of the PPLA-Q to assess the psychological and social domains of Physical Literacy in the Portuguese PE context for grade 10–12 (15–18 years) adolescents.