18. Zeigarnik Effect 18/20

This is a psychological effect that shows that people remember interrupted and unfinished actions better than others. According to this law, unfinished tasks remain in the user's memory longer than completed tasks. The design recommends notifying the user that an action is incomplete, thus increasing the likelihood of its completion. You can also use indicators or trackers that will show the degree of completion of the task, thereby attracting attention to bring the action to the end. The examples are: the degree of profile completion, an incomplete purchase on the site (basket), a loud title that is interrupted to intrigue the user, etc.