The development and validation of a Declarative Tactical Knowledge Test (DTK-T) in volleyball*

This study aimed to develop and validate a test (DTK-T) to assess the Declarative Tactical Knowledge (DTK) in young volleyball players. Accordingly, 222 players (mean age 14.37 ± 1.37) and 20 coaches were sampled. The players were classified into beginners and experts based on their years of training. The DTK-T was developed and validated through forward-backward translation, pilot testing, item analysis, content and construct validity, and reliability analysis. A Receiver Operating Characteristics (ROC) curve was built to establish which DTK-T score better identified more trained players. Construct validity analysis demonstrated a moderate test's ability to discriminate differences between beginners and experts. According to ROC analysis, 15 (on a maximum of 24) was identified as the score that better discriminates between groups (AUC = 0.78; accuracy = 0.74; sensitivity = 0.92; specificity = 0.50). The reliability of DTK-T over time was also verified (ICC = 0.80, 95%CI = [0.54,0.92]). These results indicate that the DTK-T possesses properties suitable for measuring DTK in young volleyball players.