Quantifying police officers' arrest and self-defence skills: does performance decrease under pressure?

This study investigated police officers' performance on five selected arrest and self-defence skills that are regularly used in the line of duty. In Experiment 1 a 5-point scale to measure skill performance was developed and tested with 14 police instructors. Results showed that the new scale has satisfactory inter-rater reliability and good intra-rater reliability. In Experiment 2, the external and concurrent validity of the scale was tested by measuring the performances of 19 police officers executing the same skills in a high- and a low-pressure environment and comparing the results obtained with the new 5-point scale with results obtained with a currently used binary scale (i.e. sufficient/insufficient). While the scale proved to have good external and concurrent validity, it appeared that the police officers' performance really suffered under pressure. Given the criticality of successful police performance, it is suggested that incorporating psychological factors (e.g. pressure) in training procedures may enhance performance.