Reliability and validity of an observational system to qualify performance indicators in goalball matches: Scal-Go proposal

Abstract

Which situations compose the success and failure in goalball matches? Our aims were to develop a scale to assess performance indicators in goalball and, to evaluate this proposed scale according to contextual variables (i.e., team level, match outcome and match status). Non-participant match observation method was applied in 24 goalball matches from the Paralympic Games 2016. Firstly, an observational system development was composed by performance indicators (named as Scal-Go). Success and failure from offensive and defensive phases were stratified into a spreadsheet. Following, inter and intra reliability stages were conducted together with content validity, certified by goalball’s experts. Scal-Go achieved high agreement levels for inter- (.752 and .919) and intra-observers (.846 and .974) reliability. Also, content validity was certified by goalball experts. The results showed high frequency of standard preceding actions (80.3%), strongly appropriate defences (57.8%), and acceptable attacks (57.4%). In addition, since players’ performance was associated to contextual variables, specific actions and situations are performed differently within team levels, match outcome, and match status. Match interruptions, accurate shots, goal scored first, quick defences, defensive infraction and penalty situations must be included in training process.