Project Description

Project Description


“Expected behavior” is a term for what users believe they know about how an application will work. These preconceived notions impact how users approach any new product. Where do they come from? From existing applications and product. From our mental models about how the world works.
When we design something new we must build on existing mental models or our users will be frustrated.

” The Google CRM application was not being used. I was told to discover why. After interviewing and watching the customer reps at Google it became clear that the interface we’d designed didn’t match how they did their job. Our mental model and the customer service reps’ mental models were entirely different.”


Case Study, Google CRM Application

What it is.

Every culture and subculture shares mental models of how the world works. From an understanding of how to use the public transportation in a particular city, to how to order coffee at Starbucks, to how Google search works.


How it’s used.

Users bring to your product an expectation of how it will function, based on their own mental models. Product designers try to understand what those models are when designing new products or applications.


Many of our mental models overlap. Starbucks customers in the US know what a Grande Latte is, and that they must order and pay for the coffee before they pick it up from the barista. But if you don’t live in the US, or you don’t buy your coffee at Starbucks, you may have a different mental model about how to buy a cup of coffee.

mental Models

Even within much smaller cultural groups — say a city or community — mental models differ. When I first moved from NYC to San Francisco, I found the difference between how the NYC subway worked and San Francisco subway confusing and frustrating. My mental model of a subway system overlapped enough with that of San Francisco’s so that I could figure out how to use it. But I had to learn entirely new customs (for instance, why do BART riders all line up before entering the trains? It’s not efficient.) Those differences made my first few weeks of using BART painful, and I wouldn’t have kept at it if I wasn’t forced to.


Models in conflict cause user frustration

Anyone that has grown accustom to buying coffee at Starbucks, then bought one at Phils will experience the same confusion and frustration. As product designers, we try to eliminate painful mismatches between mental models so our users will keep using our products.

The first step in any design process is to understand your users. That means learning how they see the world, and working within their expectations. If you don’t, your users won’t want to use your product.


  • Understand the mental model and its role in product design

  • Experience a mental model mismatch

  • Learn to apply the results to your designs

Tips & Tricks

Think about:

  • Differing mental models
  • Context & previous experiences
  • New users & experienced users


Your Assignment

Uncover a mental model.

Describe in as much detail as you can the steps for one of these common practices in your city:

  • Ordering a cup of coffee at a local coffee shop
  • Using public transportation to get to work or school
  • Using the elevator in a building you’ve been in

The devil is in the detail, so be as granular in your descriptions as possible.


Write up your results and share them in the comments and/or on Dribbble and Twitter #100daysdesign.