I’m a firm believer that every good application designer is an amateur behavioral psychologist at heart, and this conviction was reinforced (again) by two different product strategy sessions I participated in recently.
Because I tend to work with startups at the earliest phases of the customer adoption cycle, I spend a lot of time thinking about the emotional experience early customers have when they first discover the application, and what motivates them to engage more deeply, come back, and (best case) share it with friends.
The Zeigarnik Effect is one of a handful of behavioral heuristics that comes up again and again in these conversations. The narrow definition of this term is ‘the human tendency to remember tasks that are unfinished more indelibly than those that have been completed’, but in practice the definition is broadened to mean ‘an unconscious appetite to carry a task to completion rather than abandoning it midstream’.
Used wisely, the Zeigarnik Effect can be a powerful lever to draw customers more deeply into an application. By setting up initial engagement processes as a sequence of simple tasks (e.g., with a progress bar or step numbers that indicate where you are in the flow) it’s possible to lead users more deeply into the application’s promise than they would likely venture without scripting. This approach can also backfire if each step provides insufficient ‘payoff’ for the effort required, or if the tasks include steps that cross over into sensitive emotional territory (e.g., by crossing privacy boundaries).
In my mental framework (though this is probably stretching the idea too far), this effect is a close cousin to what Amy Jo Kim calls “The Power of Completing a Set” in her excellent outline of social gaming dynamics.