RESTQ-Sport 77 Athlete Self-Report Measure for Soccer Players :The Revisit using Item Response Theory

Abstract Monitoring athletes’ well-being by using subjective or objective approach is oneof the important aspects to ensure optimum performance for both technical andphysical during match or training. Athlete Self Report Measure (ASRM) is one ofthe subjective approaches and it is used widely at the global level. However, mostASRM are still printed on paper RESTQ-Sport is one of the well-known ASRM andit is established using Classical Test Theory (CTT). This study aims to re-validateRESTQ-Sport via a different approach; by implementing Item Response Theory(IRT) which will convert ordinal data to interval data for a sound and prudentobjective measurement. A total of 45 respondents volunteer to participate in thepilot study; and based on the interaction between respondents (person) and items, areliability index of 0.95 and 0.93 is recorded for both person and item. The responsefor this pilot study yields an explained variance by measures of 53.2%, while 9.2%is the unexplained variance. Further scrutiny is made for improvement, and thetest is re-analyzed. It is evident that the explained variance by measures improvetremendously to 56.9%; whilst the unexplained variance is reduced to 5.4%.