The interaction between tactical knowledge and consciousness makes it difficult to measure the knowledge and understanding of a game. However, Gutierrez et al. (2011) designed a game performance evaluation tool (GPET) that is an observational system for notational analysis of the tactical decisions of a soccer player. The purpose of this study was to validate the GPET in Iranian soccer schools. Forty-eight experienced (at least 3 years of experience in a national league) and inexperienced soccer school under-11 (10 years, ^0.9), under-14 (13 years, ^1.02), and under-18 (16 years, ^1.3; all groups include 8 experienced and 8 inexperienced players) players were asked to play 6 small-sided soccer games 3 v 3 with PEER-REVIEWED ORAL PRESENTATIONS S65 Downloaded by [Deutsche Sporthochschule Koeln] at 02:21 20 July 2016 a goalkeeper on a 25-m £ 35-m pitch. The games were recorded with a digital camera at a height of 5 m from the pitch and were then coded by the GPET. After consulting with 6 physical education experts and coaches to rate and revise some behavioral descriptions, the Content Validity Index tool was found to be 0.99 in offensive behaviors of players on and off the ball in all 3 age groups. To investigate intraobserver reliability, the videos of the mentioned games were randomly selected and the observations of 2 observers were compared at an interval of 2 weeks. The results of tactically appropriate behaviors such as ball possession, attacking the opponent’s goal, and scoring were positively correlated with each other (r ¼ .81, .88, .97, respectively). To evaluate interobserver reliability, the coding of 2 trained observers of the videos was compared. The results showed a high agreement between observers in tactical and technical variables (kappa ¼ .72). The GPET benefits soccer coaches in evaluating learners’ offensive behavior performance in on- and off-the-ball situations, according to the tactical situation at the present moment.
