Design Products That Shift Behavior

A Model for Creating Engagement

In product design, we look for unmet user needs and that elusive white space through which we may enrich someone’s life. But that’s not nearly enough to create a successful product. How will users adopt your product into their cluttered lives? How will we ensure that we’re not just creating yet another functionally beautiful product that never quite catches on? The answer is incorporating a strategy for user behavior change in the design process.

Designing for Use

To cite Don Norman’s The Design of Everyday Things, we have 7 principles of good design to consider when practicing user-centered design. I’ll quickly summarize them here:

  • Discoverability: the user can learn how to use the product naturally
  • Affordances: the product inherently communicates what it can do or how it can be used
  • Signifiers: the characteristics of the product that communicate its affordances
  • Feedback: signals that tell the user if they are erring or using the product correctly
  • Conceptual Model: a mental model that explains the product and its capabilities
  • Mapping: the connections of the product’s controls to it’s actions
  • Constraints: the framework within which the product can be used

If we incorporate those seven components as intuitively, humbly, and efficiently as possible, we may get to a well-designed, user-centric product. We’ll have something that people can adopt and use easily. And if it’s a solution to a user need, then bravo! We may very well have a great product to bring to market. Let’s bust out the Macallan and pour a round!

Ehh…not so fast. Sorry, no celebration scotch yet. Chances are your prospective users are already meeting that need you’re designing for in one way or another. I’d bet money that someone has already designed a solution, or people have found a suitable workaround. Thanks Industrial Revolution, globalization, Internet… We now have a superfluous amount of products to meet about 99.99% of our needs. Yet all hope is not lost. We can do better than the sea of crap solutions out there! How? We design for engagement shift, versus engagement creation.

A Model for Behavior Creation

We can credit BJ Fogg for his Behavior Model, which shows what variables need to be present for a behavior to occur:


Behavior is the product of Motivation, Ability, and Trigger. Let’s briefly dive into this:

Think about the act of answering your phone.

Scenario 1: If you’re motivated to answer it (Motivation), and you have it with you (Ability), but you don’t hear/feel the ringer (Trigger), you don’t answer it. The behavior doesn’t occur.

Scenario 2: If you don’t want to answer it, you have it with you, and you hear the ringer, you don’t answer it. The behavior doesn’t occur.

Scenario 3: If you want to answer it, you’ve visibly locked it in your car along with your keys, and you see it’s ringing, you don’t answer it. The behavior doesn’t occur.

It’s important to grasp the effect of variability and scale on each of these variables. For example, Ability may be low but a high Motivation with the presence of a Trigger will still result in a Behavior.

We could go through each permutation here, but this simple anecdote is sufficient. Fogg’s model is helpful in understanding how a behavior is formed. However, our busy, multifaceted lives are overflowing with so many behaviors that it’s myopic to only focus on creating them. We must also understand how to change them.

A New Model for Behavior Change

Let’s consider a new formula:

∆B = TF∆E

Change in Behavior is the product of Trigger, Forecast, and Change in Effort. Let’s dissect:

Trigger: we must either supplant an existing trigger, or generate a new one, that’s inextricable from an internal cue

Forecast: the affective future state we pursue

Change in Effort: the removal of friction or reduction in cognitive load (to be mathematically accurate it’s really -(∆E) but that looks messy)

To demonstrate, let’s look at Instagram through this model. We had other existing means of sharing our lives when Instagram was introduced: Facebook, Twitter, Tumble, etc. However, Instagram created a better Trigger: share photos of moments. A photo says so much more about a moment than 140 characters. The Forecast was similar to other social networks: increased status, social acceptance, fame, etc. But what really propelled Instagram forward was the ∆E. The process of sharing a moment through Instagram is nearly frictionless. You don’t have to compose a sentence, nor execute a multi-step upload and posting process. Once you take the picture, you can share it with two taps. This becomes a powerful heuristic leading to habitual use and a very high ∆B.

So Many Models!

I’m sure that many smart people have proposed other, and equally valid, methods for behavior change. I’m simply proposing a focused model to examine the relationship between what I’ve found to be the main ingredients for behavioral shift, versus generation. If we incorporate ∆B=TF∆E in our product design process, we humble ourselves. We take into consideration the convoluted interconnection of heuristics, behaviors, motivators, needs, and provocations to design products that people use more than once.

Thanks for reading! Shoot me an email if you want to chat about product design/strategy: or check out some work at