Recently, the Tactical Assessment Instrument in Football (TAIS) was developed to address football's tactical requirements in terms of game phases, learners' roles, and organizational levels of play. In this study, we sought to evaluate the psychometric properties of this existing instrument in the Physical Education (PE) context and for youth sport teams (ages 8-12 years). Our research design involved: (a) participants playing 37 football games, (b) assessing participants via observation with the TAIS and (c) conducting psychometric analysis on the obtained assessment data. For the psychometric analysis, we carried out our work in four phases: (a) a statistical analysis of the evaluation criteria, (b) analysis of the instrument's structural dimensions, (c) internal item reliability analysis, and (d) provision of evidence for external validity. Participants were 592 children (156 girls, 436 boys; ages 8-12 years) from 74 PE classes or sport teams (from three institutional contexts - schools, community-based sports, and sports clubs) in Spain. We selected 12 tactical criteria and grouped them into four theoretical dimensions (appropriate attack, inappropriate attack, appropriate defense, inappropriate defense) to confirm the instrument's structural dimensions. The Cronbach alpha and Omega McDonald coefficients were greater than .70. The TAIS discriminated between participants from the three institutional contexts, offering evidence of the instrument's external validity. Thus, the TAIS now has sufficient psychometric support for assessing learning of football tactics in PE and youth sport teams. This instrument facilitates an ecological assessment of youth players' understanding of football tactics through four theoretical tactical dimensions and 12 criteria involving information about four learners' roles (both attack and defense, on- and off-the-ball) and three organizational tactical levels of play (whole team, small groups of learners, and individual learners).
Keywords: ecological assessment; game assessment instrument; game-based approaches; sport pedagogy; youth football.