A Novel Approach to Assessing Validity in Sports Performance Research: Integrating Expert Practitioner Opinion into the Statistical Analysis

Kyprianou E., Lolli L., Al Haddad H., Di Salvo V., Varley M.C., Mendez Villanueva A., Gregson W., Weston M.

Purpose:
The purpose of this study was to demonstrate how expert practitioner opinion can be used to determine measurement validity using elite youth soccer players’ maximal sprinting speeds collected from a criterion and non-criterion measure.

Methods:

Fifty expert soccer practitioners from around the world were surveyed on issues relating to the measurement of maximal sprinting speed.
Twelve elite youth soccer players performed two maximal 40 m sprints, measured by 10-Hz GPS units (non-criterion) and a 100-Hz Laser (criterion).
Statistical equivalence bounds were set based on practitioner opinion of the practically acceptable amount of measurement error for maximal sprinting speed.
Agreement between GPS and Laser measurements was assessed.
Results:

Survey respondents reported various methods for deriving maximal sprinting speed, but most did not assess system validity.
The median value of the practically acceptable amount of measurement error for maximal sprinting speed was determined to be 0.20 m/s.
Maximal sprinting speed measured by Laser was 8.79 ± 0.33 m/s, and by GPS was 8.75 ± 0.32 m/s, with a mean difference of 0.04 m/s (90% confidence interval −0.03 to 0.11).
Equivalence testing, using the median acceptable amount of measurement error, showed Laser and GPS as likely equivalent measures (probability 93.7%).
Conclusion:
The study concludes that using expert-informed equivalence thresholds represents a novel way to assess validity in sports performance research. This approach provides valuable insights into the practical acceptability of measurement error and enhances the interpretation of measurement validity in sports performance assessment.