In a study published in 2023 in Psychological Science, Calvin Lai and Jaclyn Lisnek evaluated a diversity training program with nearly 3,800 participating officers in 251 trainings. The one-day program was conducted by a well-regarded outside organization and focused mainly on implicit bias. Based on self-reports from the training participants, the study authors found that participants’ knowledge about bias increased. However, they found little evidence to suggest that the trainings led to changes in the officers’ behavior. The authors suggest that diversity trainings in police departments could be made more effective by incorporating them into broader organizational initiatives, having police managers follow up on the lessons, and measure outcomes as part of job performance.