Editor's Note: In the everyday life of product design, the term "mental model" is actually quite common, but it is worth noting that the user's mental model is evolving. For the evolving mental model, how should product design, research and development personnel grasp it? In this article, the author has answered this question, let's take a look at it together.

"Mental model" has become an everyday term for product design: designers want to design for the user's mental model, researchers want to understand the user's mental model, and product managers want to create products that "serve the mental model of most of our customers"

Yet despite all the discussion, the value we derive from mental models is limited. Because we focus too much on the user's current mental models and ignore how they evolve over time.

First, a short introduction to the mental model

Beginning in the 1980s, the frequency with which "mental models" appear in the academic literature rose rapidly. But why is it mentioned so often? Because it is one of the main drivers of human behavior.

Mental models are mental representations that are the outcomes of our interactions with the world around us*. It is an explanation of someone's thought process about how something works in the real world. It is a representation of the world around it, the relationships between its parts, and one's intuitive perception of one's actions and their consequences.

Kenneth Craik is credited with being the first to make this point (1) (1943). In 1983, Don Norman wrote an article (2) that sparked widespread use of the term outside of academia. Five years later, Norman mentioned the term again in his book He Design of Everyday Things (3). Since then, mental models have begun to play a role in application areas such as design.

Mental Characterization*

Refers to a hypothetical inner cognitive symbol capable of representing external reality; or refers to a mental process that utilizes a certain symbol.

Mental representations can refer to mental images of things that do not actually exist in the senses, such as the taste of barbecue in memory, or to express things that individuals have not experienced or do not exist: imagining yourself on a journey in a place you have not been, or having a third arm.

(Source: Wikipedia)

Norman proposed three models that exist in design: the design model that exists in the designer's mind, the user's "s model" in the user's mind, and the system image that exists in the thing itself.

A typical design goal should be to work toward consistency, or at least the user model and system appearance. If there is a deviation, product problems will arise in large numbers, and the user experience will be affected. Therefore, the design needs to be combined with the user's existing mental model, which is a long-term practice-tested conclusion.

Second, mental models are not born with users

The mental model exists statically in user cognition, but it is not eternal and is not static. It will constantly adapt and create new experiences as users upgrade from existing products or new products emerge.

When users use a product, they can choose one of three behaviors:

Use existing mental models;
Changing existing mental models;
Create a mental model of the whole mind.

How users choose depends on a lot of factors, and we won't discuss these in the article for the time being. But we realize that today's designers focus almost exclusively on the first behavior.

Of course, for designers, the user's existing mind is very valuable. But if we can understand how users construct these mental models and how they evolve over time, this will yield greater value. Based on this, not only can products that conform to existing mental models be designed, but also can help users more easily respond to product changes and master new interaction patterns, rather than being overwhelmed.

Third, the three stages of building a mental model

Let's assume that the user is just starting to get exposed to a new product or a new feature. When they begin to interact with it, mental models form with them and change over time. This change goes through three stages.

Stage 1: Familiarity

This phase determines whether the user can use their existing mental model (which may be used on other similar products) or must be built from scratch. Existing mental models may lack effective experience and may even contain false perceptions. Core elements lacking at this stage include an understanding of the language in which the product uses and a mastery of the actionable steps necessary to complete the core tasks.

Stage Two: Proficiency

At this stage, the user begins to understand the language of the product, especially these unfamiliar or technical terms. Understanding terminology and using product language is the first step in forming the foundation of the mental model. This is also the step step required to perform the basic operations that users need to know to get the desired results. Users gain enough value by learning the basic operations of the product to motivate themselves to continue using it. Users can then use this as a basis to understand the deep-seated functions of the product.

Stage Three: Mastery

Users extend their knowledge to more complex or detailed interactions based on the core functionality they already have mastered. If they can do this, users will most likely have an accurate understanding of most of the language of the product.

There are also some interesting findings: it is assumed that the user has mastered the language and core interactions of the product. However, if the product experience exists at a certain depth, users will begin to understand the more abstract concepts, strategies, and features in the product that are not directly displayed at the UI level. Regardless, users will find them when they try to accomplish more goals.

For example, a medical professional may have learned to use the "Other Health Issues" field in a health record app as a "reminder box" for an unfinished task, rather than the "unlisted health problem information" that designers would expect. Users do so because they find it simpler and more effective than the to-do task feature designed. This innovative thinking emerges when users build more complex mental models on top of what they build at an early stage.

At the same time, at this stage, users not only have general experience applicable to the entire product, they will also develop some small "expertise" that serves a specific situation or context.

Going back to the example of health record applications, doctors have been using a single strategy to record patient information during a visit. And now, he's starting to understand how to use the product to handle the nuances between different patients (new and old, complex and simple, etc.). He has mastered all the functions needed to fill in cases during and after his visit. And with the help of graphing software, he can more effectively handle different types of context-driven tasks to help him develop a unique understanding of different types of patient subcases.

As can be seen from this three-stage model, the development of mental models is first based on a basic understanding of the product, and then uses this initial model as a basis to build a more complex model. As mental model evolution becomes deeper, users' goals and motivations that initially drive them to use the product will gradually be met.

Application of the four- and three-stage model

Now that we understand the basic process of building a mental model for users, let's apply this model to improve the product experience.

1. Use the three-stage model as a guide or tutorial design guide

Familiarizing new users with a product requires a whole new mental model. While users are being guided by the product, they are building mental models that guide their future choices and decide success or failure.

The product's bootstrap or tutorial design can be helpful for users to effectively build along a three-stage model. For example, if you find that your product requires users to understand more complex functionality before they can master the product's basic language, problems can arise. Users may have difficulty quickly building an accurate mental model, or even abandon the use of certain features.

Remember, it's much harder for users to "forget" a bad mental model than it is for them to build an accurate model the first time.

2. Evaluate the product as a set of heuristics for each stage

The different phases of the build can also be used as criteria for evaluating the design of interfaces, interactions, or task flows. Using this approach is simple, and as with other popular Heuristic Evaluation standards, they rely on a set of established design principles (4).

3. Evaluate mental models regularly

When releasing a new product or new feature, users need to spend some time building mental models. One way to understand the state of a user's mental model is to conduct regular studies, or even studies of the same participants, which helps to grasp the generalization of the user's mental model at different time stages.

Regularly get overviews of user mental models, especially when new features are released, which can help you quickly identify and diagnose problems and identify ways to build accurate mental models for users. There are many ways to evaluate mental models and will not be discussed in this article. But if used properly, common research methods such as interviews and questionnaires can accurately grasp the user's mental model.

5. Concluding remarks

Mental models are a core component of our mental decision-making process. This simple concept has long been incorporated into the process of designing the best products and has changed the way we understand users. If we take it a step further, not only focus on the mental model that already exists, but also consider how the mental model of the product is actively evolving. We will discover deeper value to drive excellence in our product experience.

Evolutionary mental models