“…In addition, personalization (32,34,35,47,57,63), autonomy (48, 64), user community groups (32,34,36,42,44,62,65,66), motivation (21), and gami cation (21,33,35,44,53,56) are cited as effective techniques to engage users. In terms of intervention construction, basing the intervention on a theory (33,47,50) whether speci c to digital interventions (33) or behavior change models (50), has been found to be effective. Additionally, using BCTs (behavior change techniques), which are the smallest active components of an intervention that are capable of changing behavior, has proven to be an effective tool for engaging users (37).…”