Development and validation of the Referee Training Activity Questionnaire (RTAQ): towards a better understanding of the training practices of soccer match officials

INTRODUCTION
As the training of soccer referees is typically self-led, direct observation and monitoring of training is seldom possible (1). Consequently, relatively little information currently exists on the training practices of soccer referees (2). Efficacious and accessible methods of monitoring referee training are therefore required. Accordingly, we sought to develop and validate a novel measurement tool, termed The Referee Training Activity Questionnaire (RTAQ), for assessing the training practices of soccer referees.
METHODS
To develop and validate the RTAQ, we employed a systematic multi-stage process: 1) item generation; 2) assessments of content and face validity; and 3) assessments of criterion validity (3). In stage 1, we generated items based upon a review of the literature and semi-structured interviews with a sample of refereeing experts (n = 8). In stage 2, items were assessed for content and face validity by a sample of referees and academics experienced in questionnaire design (n = 6), with the content validity index (CVI) calculated (4). In stage 3, a sample of referees (n = 25) completed the RTAQ and subsequently recorded a detailed 7-day training diary. Additionally, we obtained objective estimates of physical training activity through heart rate data which was used to corroborate the self-report data of the training diaries. 
RESULTS
Following stage 1, we constructed the preliminary RTAQ to include items pertaining to: 1) general training information (16 items); and 2) specific-training practices (66 items). In stage 2, content validity was confirmed for 66 items (CVI ≥ 0.78) with 16 items being deemed invalid (CVI < 0.78). We used participant feedback, alongside content validity indices, to discard or revise problematic items. In stage 3, estimates of training activity derived from the training diaries and heart rate monitors were found to be strongly related (r > 0.96; P < 0.001). Additionally, negligible mean biases, moderate 95% LOA, and significant correlations were observed for most items with those exhibiting insufficient agreement (11 items) subsequently excluded or modified as per participant feedback. 
CONCLUSION
The present results provide initial evidence that the RTAQ is a valid and reliable means of acquiring insight into the training practices of soccer referees. The development of a self-report measure in the form of the RTAQ will provide practitioners and researchers with a practical means of monitoring the training practices of soccer referees.