This research was to investigate the psychometric characteristics of the electronic protector cognition scale by the infit and outfit of taekwondo athletes. Methods: The research tools utilized the existing research of Jeon Ik-ki (2008), which conducted a survey of male and female athletes of 19 participating countries at the 19th Taekwondo World Championships. The electronic protector cognition scale used a five-point Likert grading with 1 (not at all) to 5 (very likely). Analysis using IBM SPSS STATISTICS version 23 (IBM SPSS, Inc., Chicago, IL, USA) was conducted for the 226 data sets collected. WINSTEPS 3.74 (Linacre, 2015) was used for calculating subject reliability, item goodness-of-fit, scale propriety, and item level of difficulty, in order to apply the item response theory to the psychometric characteristics of electronic protectors. The research results showed that it was suitable for subject infit/outfit in taekwondo electronic protector cognition scale as 1.00~1.01 and the input/output of taekwondo electronic protector cognition scale as 1.00~1.01. Secondly, five-point scales were reviewed to be suitable for scale propriety, resulting from stage index judgment. Thirdly, 8 items showed problems in item goodness-of-fit. Finally, scale propriety was reported to be suitable considering the ability distribution of taekwondo players and the level of scale difficulty.
Keywords: Rasch; electronic protector; item response theory; scale; taekwondo.