Mental Models

Have you ever looked up directions on Google Maps only to arrive at your destination and find that it isn’t there? Or decide to walk between two metro stations because they appear close on the map, but then find out that they were actually miles apart? Maps can be so deceiving sometimes. 

But as Polish-American philosopher and engineer Alfred Korzybski once pointed out, “The map is not the territory.”¹

By this, Korzybski was referring to the fact that people often confuse models of reality with reality itself. While maps help us to understand the layout of a place and to navigate our way around, they are just a reductive representation of what’s really out there. If they were a perfect copy of the physical space, they would no longer be of use to us (and unlikely to fit into a mobile app). 

The relationship between the map and its territory, or between perception and the actual reality, captures the idea behind mental models.

Mental models refer to the internal representations of external reality that individuals use to understand, interpret, and navigate the world around them. They consist of a set of beliefs, generalizations, and assumptions that make up our worldview. And because our worldview affects how we interpret experiences, these mental models also influence our thoughts and behaviours. Most of the time, we may not even know that mental models exist or that they are impacting our decision-making and actions. They are constructed by individuals based on their unique life experiences, perceptions, and understandings of the world.

So where do mental models come from? And how do we create them in the first place? Mental models are constructed by individuals based on their unique existing beliefs, perceptions, and understandings of the world.² That is, mental models are born out of prior experience and can influence our expectations about how things will function in the future. 

Our mental models are not static and are constantly evolving and refining based on our real-world experiences. As such, mental models are highly individually subjective; while we all live in the same world, we construct different mental models of how it works. That being said, there are hundreds of fundamental mental models—such as velocity, reciprocity, and relativity—that humankind has developed throughout history and that we use in our everyday lives to help us understand complex processes.

System image: a term coined by Donald Norman to describe the information available to us regarding how to interact with a device, such as appearance, past experiences, sales literature, advertisements, articles, and instruction manuals. 

Card sorting: A research method used to help designers understand users’ mental model of a system. In a card sorting test, users are given a set of cards containing topics or information and asked to organize these cards into categories. Observing how users group these cards can help designers decide where to place information on a website, how to structure help pages, or how to group topics in navigation menus.

Human-computer interaction: an interdisciplinary field that focuses on the design and utilization of computer technologies, emphasizing the interaction between users and digital systems to optimize user experience and interface usability.

Inference rule approach: involves employing formal logic and deductive reasoning principles to model how individuals draw conclusions and make inferences, emphasizing a structured and rule-based framework in understanding cognitive processes.

The concept of mental models isn’t the invention of a single person, but rather the result of the combined work of various researchers and practitioners in the fields of psychology, cognitive science, philosophy, human-computer interaction, and business. Most histories of mental models start in 1943 with the Scottish psychologist Kenneth Craik. In his book The Nature of Explanation,³ Craik introduced the idea of internal models of the external world that could be manipulated to guide future actions.⁴ This early sketch of a theory laid the foundations for the concept that would later be known as mental models, and is worth quoting in full:

Kenneth Craik: Scottish psychologist and philosopher whose book, The Nature of Explanation, laid the foundations for the concept of mental models. One of his most influential views was the idea of human beings as information-processing systems. 

Philip Johnson-Laird: British psychologist and expert on the psychology of language, reasoning, and thinking. His mental model theory of reasoning, published in his book Mental Models has been influential across a variety of domains. 

Peter Senge: American systems scientist who developed the idea of the learning organization. Senge emphasized the importance of understanding and challenging mental models within organizations to promote learning and innovation.

Mental models act as filters through which individuals interpret and perceive the world. They play a crucial role in decision-making by helping individuals assess risks, predict outcomes, and choose appropriate courses of action. Mental models can also impact the way people communicate with each other. When individuals have shared or compatible mental models, they are able to communicate effectively. Conversely, misunderstandings and conflicts can arise when people have different mental models of a particular concept or situation. 

In product design, understanding and integrating mental models is essential for creating user-centric and intuitive experiences. Mental models represent users' preconceived notions, expectations, and cognitive frameworks, and designers leverage this understanding to align product interfaces and interactions with users' mental models. By incorporating familiar metaphors, consistent navigation patterns, and intuitive workflows, designers can reduce cognitive load, enhance user comprehension, and create a more satisfying and user-friendly product experience.

It’s important to note that mental models are incomplete representations of reality since peoples’ ability to represent the world accurately is always limited and unique to each individual.⁹ This could be described as a many-to-one mapping from possibilities in the world to their mental model. As we saw earlier with the map and territory example, we can be tricked into thinking that our mental models represent true reality. When our models don’t live up to that reality, this can lead to confusion, disappointment or frustration. Likewise, because our mental models are based on past experiences and shape our expectations for the future, they may give us unrealistic expectations when confronted with new situations. 

Since the 1990s, mental models have been caught up in a debate about the nature of human reasoning. The controversy arises from whether humans reason deductively by constructing mental models and reviewing them, or by following built-in inference rules of mental logic. While Byrne & Johnson-Laird’s¹⁰ argument that human reasoning relies on the construction and manipulation of mental models has consistently been more popular, many scholars have defended the inference rule approach:¹¹ a function which takes premises and returns a conclusion. 

Mental models for COVID-19

In times of crisis, mental models become essential for helping us to perceive, understand, and make decisions based on the complex information we receive. Whether we were aware of it or not, these simplified representations played a crucial role in helping us to navigate the significant disruption and uncertainty of the COVID-19 pandemic. 

Various studies have explored how people used mental models to make sense of and act upon COVID-19 related scientific information. In a qualitative study conducted by Berg et al., participants were asked about their beliefs regarding various aspects of COVID-19 including virus transmission, exposure, and health effects. The study followed the mental models framework¹² which involved creating an expert model based on scientific literature and guidelines and then comparing this with the public’s mental models. The researchers found that some people preferred to understand why certain behavior and activities were considered high-risk, while others just wanted simple messages explaining what to do to protect themselves.¹³ The findings of this research underscore the fact that there is no one-size-fits-all approach to public health risk communication. A mental models approach can help health officials develop targeted and balanced risk communication that empowers people with decision-relevant information. 

In another series of studies, de Ridder et al. found that people constructed their own complex mental models which consisted of a range of factors including virus characteristics, governmental mitigation measures, and their own behavior.¹⁴ In particular, their findings demonstrated a correlation between people’s level of satisfaction with mitigation measures and level of concern and the complexity of their mental models; that is, those who were satisfied with measures and felt concerned about the spread of the virus constructed more extensive mental models with more connectedness between factors. Once again, the studies highlight the importance of considering mental models when planning public health communication. 

Mental models in human-computer interaction 

In his 1988 book The Design of Everyday Things¹⁵, Donald Norman introduced the concept of mental models to the field of human-computer interaction (HCI) and the interaction design community. Writing on user-centered design, Norman emphasized the importance of understanding users’ mental models in designing intuitive and user-friendly interfaces. 

Mental models are essential in HCI primarily because what users believe they know about a user interface impacts how they use it. In other words, based on previous experiences, users form predictions and expectations about the system and plan their future actions. And this is precisely where problems can arise. There’s often a gap between designers’ and users’ mental models because each user’s background and past experiences produce unique mental models.¹⁶

As Norman explains, systems are generally designed and implemented based on the designer’s mental model.¹⁵ Users, on the other hand, develop their own mental model of the system based on their past experiences and their present interaction with the system. The only way the designer can convey their mental model to the user is through the ‘system image,’ or the designer’s materialized mental model. This image, however, is open to infinite interpretations depending on the user and their mental model. 

Mental models for business decisions with Roger Martin

Roger Martin, one of the world’s leading business minds, joins us for an episode of The Decision Corner podcast to discuss how mental models guide business decisions and how restructuring failing mental models can help improve ourselves, our teams, and our organizations. 

Inertia

Our mental models contribute to a phenomenon called inertia: our preference to keep behaving as we already are and tendency to resist changes in our ways of thinking. This reference guide entry explores the history of research around inertia, its role in decision making, and how it impacts our lives. 

1. Korzybski, A. (1931). A Non-Aristotelian System and its Necessity for Rigour in Mathematics and Physics. Paper presented at the American Mathematical Society, New Orleans, Louisiana A.A.A.A meeting, December 28, 1931. http://esgs.free.fr/uk/art/sands-sup3.pdf
2. Jones, N. A., Ross, H., Lynam, T., Perez, P., & Leitch, A. (2011). Mental Models: An Interdisciplinary Synthesis of Theory and Methods. Ecology and Society, 16(1). 
3. Craik, K. J. W. The Nature of Explanation. Cambridge University Press. 
4. Campello, D. (2020, 7 May). Today, 7th May, marks the 75th anniversary of a fatal accident that changed the course of Psychology in Cambridge. Department of Psychology, University of Cambridge. https://www.psychol.cam.ac.uk/news/today-7th-may-marks-75th-anniversary-fatal-accident-changed-course-psychology-cambridge
5. Sieniutycz, S. (2020). Complexity and Complex Thermo-Economic Systems. Elsevier. 
6. Princeton University. (n.d.). Philip Nicholas Johnson-Laird. Princeton University Office of the Dean of the Faculty. https://dof.princeton.edu/people/philip-nicholas-johnson-laird
7. Johnson-Laird, P. N. (1983). Mental Models. Lawrence Erlbaum Associates. 
8. Senge, P. (1990). The Fifth Discipline: The Art and Practice of the Learning Organization. Currency. 
9. Jones, N. A., Ross, H., Lynam, T., Perez, P., & Leitch, A. (2011). Mental Models: An Interdisciplinary Synthesis of Theory and Methods. Ecology and Society, 16(1). 
10. Byrne, R.M.J., & Johnson-Laird, P.N. (1989). Spatial reasoning. Journal of Memory and Language, 28, 564-575.
11. Van der Henst, J-B. (n.d.). Mental Model Theory versus the Inference Rule Approach in relational reasoning. Thinking & Reasoning, 8(3), 193-203. DOI: 10.1080/13546780244000024
12. Morgan, M. G., Fischhoff, B., Bostrom, A., & Atman, C. J. (2002). Risk communication: A mental models approach. Cambridge University Press. 
13. Berg, S.H., Shortt, M.T., Thune, H. et al. (2022). Differences in comprehending and acting on pandemic health risk information: a qualitative study using mental models. BMC Public Health, 22, 1440.
14. De Ridder, D. T. D., van den Boom, L. A. T. P., Kroese, F. M., Moors, E. H. M., & van den Broek, K. L. (2022). How do people understand the spread of COVID-19 infections? Mapping mental models of factors contributing to the pandemic. Psychology & Health, DOI: 10.1080/08870446.2022.2129054
15. Norman, D. A. (1988). The Design of Everyday Things. New York: Basic Books. 
16. Nielsen, J., & Chan, M. (2024, January 26). Mental Models. Nielsen Norman Group. https://www.nngroup.com/articles/mental-models/
17. Interaction Design Foundation. (2015, July 5). Mental models. Interaction Design Foundation - IxDF. https://www.interaction-design.org/literature/book/the-glossary-of-human-computer-interaction/mental-models