title: Validity and reliability of questionnaires measuring physical activity self-efficacy, enjoyment, social support among Hong Kong Chinese children.
abstract: BACKGROUND
  Physical activity (PA) correlates have not been extensively studied in Hong Kong children.
  
  
  OBJECTIVE
  The aim of this study is to assess the validity and reliability of translated scales to measure PA related self-efficacy, enjoyment and social support in Hong Kong Chinese children.
  
  
  METHODS
  Sample 1 (n = 273, aged 8-12 years) was recruited (May-June, 2013) from two primary schools. Confirmatory factor analyses (CFA) were conducted to assess factorial validity. Criterion validity was assessed by correlating measured constructs with self-reported PA. Cronbach's alpha was computed to assess scale internal consistency. The intraclass correlation coefficient (ICC) was performed to assess scale test-retest reliability. Criterion validity was further examined in Sample 2 (n = 84, aged 8-12 years) from a third school by correlating measured constructs with objectively measured PA collected in September 2013 and February 2014.
  
  
  RESULTS
  The CFA results supported the one-factor structure of the scales. All PA correlates were significantly (p < 0.01) associated with self-reported PA in Sample 1. Self-efficacy and enjoyment were significantly (p < 0.05) correlated with objectively measured PA in Sample 2. All the scales demonstrated acceptable internal consistency. All ICC values of the scales suggested acceptable test-retest reliability.
  
  
  CONCLUSIONS
  The results provide psychometric support for using the scales to measure PA correlates among Hong Kong Chinese children.
authors: Department of Physical Education, Hong Kong Baptist University, Hong Kong.
authors: Yan
authors: Y
authors: Liang
authors: Department of Physical Education, Hong Kong Baptist University, Hong Kong.
authors: Patrick W C
authors: PW
authors: Lau
authors: Department of Physical Education, Hong Kong Baptist University, Hong Kong.
authors: Wendy Y J
authors: WY
authors: Huang
authors: National Institute for Health Innovation, University of Auckland, New Zealand.
authors: Ralph
authors: R
authors: Maddison
authors: USDA/ARS Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX, United States.
authors: Tom
authors: T
authors: Baranowski
keywords: Children; Enjoyment; Reliability; Self-efficacy; Social support; Validity