Validity and reliability of an assessment instrument of track start in swimming

Background and Study Aim. The development and validation of assessment instruments are essential procedures for any professional intervention, including in physical education and sports contexts. This study aimed to provide a component-based assessment instrument for track start in swimming. It refers to the act of starting the competitive swim by diving into the water from a raised block (platform) at the edge of the pool. Material and Methods. The content validity involved the participation of sixty-three experienced swimming coaches. They completed a questionnaire about their degree of agreement (Likert scale) with the initial position, impulsion, flight, and entry into the water as the track start's components. Reliability and construct validity involved the participation of seven experienced swimming coaches. The first was verified through test-retest (intrarater) and reproducibility (interrater) procedures. The latter was tested by considering the instrument's ability to assess different track start performances. Results. The concordant answers (strongly agree and agree) ranged from 63% to 95%, with most components above 80%. The Intraclass Correlation Coefficients (ICC) results show from good to excellent interrater and intrarater reliabilities. Specifically, the interrater correlations in the test and intrarater correlations in track start 1 were revealed excellent. In addition, the interrater correlations in the retest and intrarater correlations in track start 2 were revealed good. Conclusions. The obtained validities and reliabilities made possible a component-based assessment instrument that allows: (i) a clear and standardized structure of track start in swimming involving the initial position, impulsion, flight, and entry into the water; (ii) accessing to the practitioners’ states in relation to desired start performance; and (iii) a reference for coaches and teachers to provide instruction and feedback for learning and performance improvement.