Understanding your users mental model

Next time you’re planning a UX design project, make time to understand your user’s mental model on the subject or product you’re working on. It’s an incredibly useful insight and will help guide your designers by highlighting gaps between what they're creating and how it's likely to be perceived by its end users.

We all build mental models, without even realising. For example - if I were to ask you how central heating works, or how to change a lightbulb, you more than likely have a list of steps in your mind.  A mental model is how, in your own mind, you think that thing works. And the level of understanding influences how long it takes to learn something new.

By understanding how the user believes a product or process works (rather than knowledge based on fact), you’ll be armed with another angle with which to design and deliver something which is quickly and easily usable. Why? Because the size of the gap between a users’ existing mental model and your design will clearly dictate the effort to learn it.

But… mental models can change

Ahh if only it were that simple eh? Your users mental models can and do change. They are affected by all kinds of external stimuli. Things they see and read online, conversations with friends and experience with similar products can all influence a mental model of something.  

Jakob’s Law states that users spend most of their time on other sites. With this in mind, it’s clear that users are going to prefer (or at least feel comfortable with) your site or product if it works in the same way as all those other examples they already know.

That said, apps and products which are used everyday (like instagram or facebook for example) can and do introduce new, small paradigm shifts frequently and get away with it because people’s expectations (and mental models) adjust over time.

If they were to attempt something more drastic, they would probably find that people balk at it, exclaiming that the app had become more difficult to use! Something we don’t advise!

You are not your users

This is probably one of my most frequently uttered phrases. It applies to everything we do as UX consultants. You are not your user and ergo, you probably don’t have the same mental model as them. Your understanding of your product is going to be different due to your expertise and experience working on it day in day out.

It’ll come as no surprise to you that I do not advocate using your own mental model in place of research with real users.

Mental modelling in practice

There are a number of ways you can go about understanding your users’ mental models. Depending on your project scope, time and budget you could try any combination of these activities:

  • Depth Interviews
  • Ethnographic research
  • Task analysis
  • Usability testing existing solutions
  • Competitor analysis

Once you’ve determined what those mental models are, you need to turn them into a conceptual model which can then form part of your information architecture, user flows, prototyping and design iteration process.

Examples of mismatched mental models

Users often apply perceived logic from similar functions and products. This can understandably sometimes lead to confusion. There are plenty of examples of this in everyday life - from products, apps and websites through to physical things.

Here are a few of my favourites:

Central heating in the home

It’s a commonly held belief that turning the home thermostat up high will warm your home up quicker.

This could be linked to our understanding of how air vents work in the car. You turn the dial and feel the heat coming out instantly. In reality though, whilst these are similar functions, these two things work differently. A home boiler turns on max immediately and stays there until the thermostat tells it the selected temperature is achieved.  

TripAdvisor app

Alot of the reviews of the Tripadvisor App in the App Store are of the hotels and feedback they’ve given or read rather than their experience using the app (which is actually what they should be writing about).  I think this is happening because some users users don’t realise that they have to download the app. Their mental model is “Search for TripAdvisor > Tap “Ratings & Reviews” > “Write a review”.

This is probably because they approach the app store using the same mental model as they have for using Tripadvisor on a web browser which is similar but missing that ‘download’ step.

Using cash machines abroad

It’s common for British people travelling in Latin America (as an example) to walk away from a cash machine without their debit card. This all comes down to mismatched mental modelling.

Here in the UK, the convention is:

  1. Insert card
  2. Enter pin
  3. Select amount
  4. Take card
  5. Take cash

In Latin America, ATMs work in a very similar but slightly different way:  

  1. Insert card
  2. Enter pin
  3. Select amount
  4. Take cash
  5. Take card

The result is that often, British visitors often leave their cards in ATMs after walking off with their cash and perhaps, when our Latin American friends are here, they walk off without their cash! I don't know which is worse.

Expecting an “Apply” button when filtering search results on a website

Historically, on most websites, you needed to press a button to apply filters after conducting a search. Nowadays, they mostly don’t work that way, with changes happening as you select each filter. but nowadays, most sites don’t work , with changes happening immediately.

On desktop, this isn’t such an issue as you can usually see the change happen. On mobile though, filters often open in an overlay, so you can’t see the consequences of your actions. This is when you’re likely to resort back to your old mental model.

Understanding is key

As experts in user centred design, it’s imperative that we get the way in which users approach the product or website we are working on both before and during any design project.  Understanding their various mental models is key to this as it shows how and where to iterate towards the most effective design.

In my experience, many of our clients’ usability issues have been caused by a gap between the conceptual model created by their designer and the user’s mental model. You can avoid these, reducing the number of iterations to get it right by finding out users’ mental models through research early on. In fact, the earlier the better.