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Mental models for designers

Mental models are how we understand the world.
Mental models for designers

A few years ago, I was presenting the designs of a complex web application to a client and his team for review.

I went through the entire process, including research, low-fidelity wireframes, testing, high-fidelity, and prototyping. Everything was gleaming. Every pixel was in its proper place. Every interaction was deliberate.

However, as I began to explain the designs and directions, I realized that the people in the room (via Zoom) were not understanding me. They were confused and didn't understand how I made decisions. Finally, I was unable to get the buy-in, and it was entirely on me.

When I sat down to reflect after the presentation, I realized a few things:

First, I failed to address how I solved the problem.

Second, I did not reveal how I made decisions.

Third, there was no story to tie everything together.

At this point, I came to the realization that being a designer involves far more than just designing. To effectively communicate my ideas and make sure they are heard and understood, I need to learn skills outside of design.

I asked myself "How can I act outside of my core design skills?". After a few hours of researching on Google, I discovered mental models.

A mental model is based on belief, not facts: that is, it’s a model of what users know (or think they know) about a system such as your website. – Nielsen Norman Group

Design is more than just aesthetics. It's also about how a product or service works and, most importantly, it's a way of thinking.

The design encourages us to interact with our surroundings and keeps us connected to the world and people. It assists us in navigating both physical and digital spaces.

Design is used to convey information. Depending on who we are, it can be influential by understanding our behavior and demographics.

As I began to learn and apply these mental models, I found it easier to communicate my decisions and ideas. But, more importantly, it became easier for me to try to convince others that my ideas were worthwhile.

Have you ever noticed how a child who has previously used a touchscreen begins to wonder when a different screen (such as a laptop or TV) does not support the swiping interaction? A child has formed an expectation (a mental model) based on their previous experience with touchscreens that swiping is how every device with a screen should behave.

Individual users each have their own mental models, and different users may construct different models of the same user interface. Further, one of usability’s big dilemmas is the common gap between designers’ and users’ mental models. – Jakob Nielsen, Nielsen Norman Group.

Designers are focused on design work and frequently build their own mental models. They also learn them from other designers who use popular interface design patterns.

In certain ways, this might lead to the creation of a "designer bubble." It's easy to fall into the trap of creating something that makes sense to other designers but may be confusing to the typical user.

People have distinct mental models that are shaped by their education, experience, age, and culture. The typical user is not as familiar with the subtle UI patterns known by designers living in the so-called "designer bubble." Designers must bridge the gap between their mental models and those of their consumers to empathize with them and create optimal usability.

These are three mental models that I use almost every day as a designer to make better decisions and solve complicated challenges.

First Principles

First Principles enables you to deconstruct complex problems into fundamental parts and then develop new solutions from there.

Many of the world's finest thinkers and doers, like Naval and Elon Musk, as well as Nassim Nicholas Taleb and Chamath Palihapitiya, highlight the significance of first principles thinking.

It's a strong problem-solving method that's also known as "reasoning from fundamental principles." Recognizing the fundamental principles of a problem will enable you to create novel solutions.

The first principle is a fundamental concept or fact that can not be further broken down. First-principles thinking involves looking deeper until you reach the very heart of the problem.

When confronted with challenging circumstances, we have a tendency to rely on fundamental assumptions that we have been told are correct (or believe to be true).

It's quick and easy to do so. However, it also leads to unimaginative, linear solutions that closely mirror everything that has come before.

Consider the solution to a problem to be a house. The assumptions that underpin the answer are referred to as the foundation.

The house will collapse if the foundation is poor. The house will stand firm if the foundation is strong. The first principles serve as a solid foundation for the house.

How to use it?

TL; DR: Take your problem and:

  1. Break it down into its fundamental parts
  2. Reconfigure those parts to build a solution

It sounds straightforward, but digging deep into the problem and discovering those initial principles requires some focused thinking.

Here are some techniques you can use that will help you:

The Five Whys

This is a famous strategy in user research in which a researcher dives deeper by asking "why" questions repeatedly. It enables you to identify the underlying causes of problems. Of course, you do not need to stop at five, but it is usually sufficient to uncover a basic concept.

Socratic questioning

Children have a natural tendency to think in terms of first principles. They, like us, want to understand what is going on in the world. To accomplish this, they intuitively use the questions games that some parents hate.

To dig for the underlying truth, there are six types of questions you might ask.

  • Clarification – "What do you mean by...?"
  • Probing assumptions – "What could we assume instead?"
  • Probing reasons/evidence – "Why do you think this is true?"
  • Implications and consequences – "What effect would that have?"
  • Different viewpoints – "What would be an alternative?"
  • Questioning the original question – "What was the point of this question?"

Hard choice model

The Hard choice model can help you understand the type of decision you're making — whether it's a no-brainer, a difficult option, or anything in between. It will allow you to proceed with your decision.

What makes a hard choice hard is the way alternatives relate.

It assists you in categorizing decisions along two axes: the decision's impact and how you may compare the options.

When you can use this model to categorize your decisions, you will be able to take the proper action.

How to use it?

TL; DR: Take your decision and look at:

  1. How impactful the decision is
  2. How easy it is to compare the options

A "No Brainer" decision has a low impact and several options that are easy to compare. It should be obvious which alternative stands out, thus it's critical to make a decision promptly.

When comparing possibilities becomes more difficult, you are faced with an "Apple/Orange" decision. It is not suggested that you spend a lot of time weighing the advantages and cons. It's still a small decision. The priority should be to make a decision as soon as possible. Even if you have to rely on your gut instinct.

It becomes more interesting when decisions have a large influence. You are dealing with a "Big Decision" if the options are simple to compare. You most likely know which option to select and only need to gather the confidence to make the selection.

When possibilities are difficult to compare, the decision truly becomes a "Hard decision." In both circumstances, it seems appropriate to postpone your decision and assess many options against one another.

What, so what, now what?

The what, so what, and now what model is a reflective model for understanding challenges and discovering new solutions. Begin with the event, then consider the consequences and create ideas.

This tool has been developed by the BDA as an aid to support reflection and is based on a framework developed by Rolfe et al.

If you go through a planned process, learning via reflection becomes more meaningful. Several models can help in the reflective process.

What? (Happened? Was I doing? Were others doing?)

So what? (Did I need to know to help me deal with this situation? Else could I have done?)

Now what? (Do I do make things better? Will I do? Might be the consequences of this alternative action?)

Using this style, you begin with the event (the "what?"), then explore the implications (the "so what?"), and finally, brainstorm potential solutions or future steps (the "now what?").

How to use it?

What? Use the following questions to stimulate the process:

  • What is the problem or issue that we are facing?
  • What happened?
  • What did you notice?
  • What was everyone’s reaction to the event?
  • What positive and negative aspects do you observe?

So What? Use the following questions to encourage the analysis:

  • How does this event affect us? How does it affect our future?
  • Why is it important? What critical questions does this information cause us to ask?
  • What emotions does the event evoke? How does it make us feel?
  • What conclusions can we draw from this experience?

Now What? Use the following questions to guide the brainstorm:

  • What do we need to do to move forward? How can we turn this event into something positive?
  • What have you learned? How will you use the insights that you discovered?
  • What will you do differently the next time? What will you do the same?
  • What hidden opportunities has this event uncovered? How can we use them for our benefit?


If we do not think for ourselves, we are imprisoned by the thoughts of others.

Reasoning from fundamental principles enables us to see what is conceivable outside of history and common wisdom. When you truly understand the concepts at work, you can determine if the current approaches make sense. Frequently, they do not.

Use these mental models when you are doing something you've never done before or dealing with complex topics. When you stop making assumptions and stop letting others frame the problem for you, your thinking improves in all of the areas.