What UX Designer Should Know About User Mental Model

Hero image. Source by sukmaraga
Hero image. Source by sukmaraga

Do you hear about the mental models? Why do we need to know about our users’ minds? Things are designed to be used by people. Without a deep understanding of people, the designs are apt to be faulty, difficult to use, difficult to understand.

Human has extremely limited short-term memory and attention, our mind is intensely occupied with a task, goal, or emotion, we focus a lot our attention and memory through our goal and attend to ignore the tools that we’re using to perform the tasks.

A good user interface should help users perform their goals instead of calling attention to the software application itself.

Think about having you ever forget about pulling out your debit card when you withdraw money from an ATM? Our short-term memory is really just focused attention at any given moment and with very limited capacity.

When we complete the withdrawal, our attentional resources focused on the tasks are fulfilled. We achieve our withdrawal goal. Everything related to it often immediately falls out of our short-term memory — forget about it. That’s why some good ATM machines have designed with a sound or blinking light in the card outlet to remind people of pulling out cards.

Limits on Attention Shapes our Thoughts and Action

We tend to focus on the goal and ignore the tools we are using to perform tasks. This happens whether we are using a computer application, online services, or interactive appliances, we think about tools superficially, and only when necessary(Johnson, 2014).

  • Indicate what users have done versus what they have not yet done. When we are designing an interactive system, we should inform users about the steps. Most email applications do this by marking already-read versus unread messages (Image 1–1). For example, in Gmail, when the email is already read, it shows most Websites do it by marking visited versus unvisited links, and many applications do it by marking the completed steps of a multipart task
image 1–1. Example from Gmail. Read vs unread email has different design states.
Image 1–1. Example from Gmail. Read vs unread email has different design states.
  • Interactive systems should allow users to mark or move objects to indicate which ones they have worked on versus which ones they have not worked on. for example (image 1–2), google keep allow users to assign a color to note. Users can use the colors to track their work.
Image 1–2. Example from Google keep. users assign color to notes and can use the colors to track their work.
Image 1–2. Example from Google keep. users assign color to notes and can use the colors to track their work.

We Follow the Information “Scent” Toward Our Goals

The tendency of people to notice only things on a computer display that match their goal and the literal thinking that exhibit when performing a task on a computer. Focusing design on match users’ goals and make interpret on what users see on a display.

People don’t think deeply about instructions, command names, option labels, icons, navigation bar items, or any other aspect of the user interface of computer-based tools. If the goal in their head is to make a flight reservation, their attention will be attracted by anything displaying the words “buy,” “flight,” “ticket,” or “reservation.”(Johnson, 2014)

As a designer, we need to understand the goals that users are likely to have at each decision point in a task. and ensure that each choice point in the software provides options for every important user goal and clearly indicates which option leads to which goal.

People Prefer Familiar Paths

While pursuing a goal, people take familiar paths whenever possible rather than exploring new ones. Why is that? are we mentally lazy? Usually, yes. Taking familiar, well-learned routes can be done fairly automatically and does not consume much attention and short-term memory which reduces the burden of energy. We tend to perform once we learn to perform a certain task using a software application, may continue to do it the same way, and never discover a more efficient way (Johnson, 2014).

As a designer, we need to:

  • Help users make mindless choices. When we design, we need to keep in mind, our users can be too lazy to learn a new more efficient way of completing a task. So given that we can provide limited options to help them use our system mindlessly. On the other hand, allowing users to become productive quickly and reducing their need to problem-solving while working.
  • Guide users to the best paths. From its first screen or homepage, software should show users the way to their goals. This is basically the guideline that software should provide a clear information scent. When they come back to the system, not only they know what the best ways are, but also they can take the best ways without any thinking because those paths are already learned and become familiar with.

But When your users become familiar with your system, you can actually show other ways that users can choose to complete tasks more quickly.

  • Help experience users speed up. Make the design easy for expert users to switch to faster paths after they have gained experience. The slower paths for newcomers should show users faster paths if there are any. This is why most applications show the keyboard accelerators for frequently used functions in the menu-bar menus.

User experience designers should consider whether the tasks supported by a system they are designing have cleanup steps that users are likely to forget, and if so, we should design the system either to help users remember, or eliminate the need for users to remember

Mental model

A mental model is an explanation of someone’s thought process about how something works in the real world. It is a representation of the surrounding world, the relationships between its various parts, and a person’s intuitive perception about his or her own acts and their consequences.

Design is concerned with how things work, how they are controlled, and the nature of the interaction between people and technology.

Today, most of the problems come from a complete lack of understanding of the design principles necessary for effective human-machine interaction. Why this deficiency? Because much of the design is done by engineers who are experts in technology but limited in their understanding of people.

When done well, the results are brilliant, pleasurable. When done badly, the products are unusable, leading to great frustration and irritation.

Two of the most important characteristics of good design that each designer should follow: (Norman, 2013)

  • Understanding. Good design starts with an understanding of psychology and technology. It requires good communication from machines to people, indicating what actions are possible, what is happening, and what is about to happen. When things go wrong, communication is especially important.
  • Discoverability. Discoverability means discovering what it does, how it works, and what operations are possible. Discoverability results from the appropriate application of five fundamental psychological concepts: affordances, signifiers, constraints, mappings, and feedback, with additional principles, conceptual model.

6 Concepts for Strong UX Design

Good design requires understanding and discoverability. Discoverability is consist of 5 fundamental psychology concepts and plus 1 — conceptual model, the most important of all concepts, provide the true understanding and bringing about the concept of the mental model.

(All of the contents below are referenced from the book of design of everyday things, Don Norman, 2013)

  • Affordances. Affordance refers to the relationship between a physical object and a person. For example, a chair affordance is for support and afford sitting. Most chairs can be lifted by a single person, afford to lift. If a weak person cannot lift a chair, then for this person, the chair doesn’t have that affordance. An affordance is a relationship, not properties. Whether an affordance exists depends upon the properties of both the object and the agent. For designers, visible affordance is critical. It provides strong clues to the operations of things. The way to help people figure out what actions are possible is called a signifier.

Affordances determine what actions are possible. It represents how an agent (a person, animal, or machine) can interact with something. Signifiers communicate where the action should take place, a singnal. Signifier must perceiveable(Norman, 2013).

  • Signifier. The signifier is the clues that the designer provides for people to search for. It is can be signs, symbols, markers, sounds, any perceivable indicator. Signifiers can be deliberate and intentional, such as the signs labeled “push,” “pull,” or “exit” on doors, or arrows and diagrams indicating what is to be acted upon or in which direction to gesture.

The signifier is an important communication device to the recipient, whether or not the communication was intended. For example, when you want to design a swipe feature for people to see the recommendation of a restaurant.

The swipe feature is affordance, which affords people to swipe. However, if you don’t tell people what to do and where to do, which means design a clear signifier, telling them where to swipe and how to swipe, people would frustrated. The affordance will fail. Another good example is the iPhone unlock screen design (image1–3). The unlock affordance is accompanied by a clear signifier that tells users to “swipe up to unlock”.

Image1–3. Example from iPhone. The unlock affordance is accompanied by a clear signifier that tells users to “swipe up to unlock”.
  • Mapping. Mapping refers to the relationship between the elements of two sets of things. A good design is consist of natural mapping, which means taking advantage of spatial analogies, leads to immediate understanding. For example, to make it easy to determine which control works which light in a large room or auditorium, arrange the controls in the same pattern as the lights. Some natural mapping is cultural or biological, as the universal standards, nodding means Yes; shaking heads means No. Some natural mapping comes from grouping and proximity, from Gestalt psychology(you can find the introduction of Gestalt Principle from here.), that can be used to map control to function.
  • Feedback. Feedback — communicating the results of an action — is a well-known concept from the science of control and information theory. Imagine trying to hit a target with a ball when you cannot see the target. Feedback must be immediate: even a delay of a tenth of a second can be disconcerting. If the delay is too long, people often give up, going off to do other activities. Feedback must also be informative. However, to remember, too much feedback can be even more annoying than too little. think about how annoying when there are a machine beeps and boops all the time informing you of a purchase success/failure. How annoying it could be. Also, too many announcements cause people to ignore all of them, which means critical and important ones are apt to be missed. Feedback has to be planned and prioritized so that unimportant information is presented in an unobtrusive fashion.
  • CONCEPTUAL MODELS refers to, usually highly simplified, of how something works. It doesn’t have to be complete or even accurate as long as it is useful. The conceptual model resides in the minds of the people who are using the product, so they are also “mental models.” Mental models, as the name implies, are the conceptual models in people’s minds that represent their understanding of how things work. Different people may hold different mental models of the same item. Indeed, a single person might have multiple models of the same item, each dealing with a different aspect of its operation: the models can even be in conflict.

The major clues to how things work come from their perceived structure — in particular from signifiers, affordances, constraints, and mappings

Conceptual models are valuable in providing understanding, in predicting how things will behave, and in figuring out what to do when things do not go as planned. A good conceptual model allows us to predict the effects of our actions. Good conceptual models are the key to understandable, enjoyable products: good communication is the key to good conceptual models.

The designer’s conceptual model is the designer’s conception of the product, occupying one vertex of the triangle.

The user’s conceptual model comes from the system image, through interaction with the product, reading, searching for online information,information, and from whatever manuals are provided.

In order to design a good user experience, the designer needs to master all of the principles and concepts.


Johnson, J. (2014). Designing with the Mind in Mind: Simple Guide to Understanding User Interface Design Guidelines (2nd ed.). Morgan Kaufmann.

Norman, D. (2013). The Design of Everyday Things: Revised and Expanded Edition (Revised ed.). Basic Books.



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Belanna Zhou

Belanna Zhou

UX|Product Designer@Cisco; Human-Computer Interaction@UMICH