Abstract: A method determines the most effective motivator at inducing a user to engage in a digital mental health intervention. The user is exposed to a first motivator that prompts the user to perform the intervention. The motivator can be a video, audio tape, textual explanation or quiz-like game. Intervention and motivator parameters are monitored to assess user engagement both with the first motivator and in performing the intervention. An intervention delivery model is personalized to the user based on both parameters. The intervention delivery model is used to determine the efficacy of the first motivator at motivating the user to perform the intervention. The intervention and motivator parameters are compared to an intervention engagement threshold and a motivator engagement threshold. If either or both parameters are below the corresponding threshold, the intervention delivery model is used to select a second motivator. The user is then exposed to the second motivator.