Mental Model Literature Review - Part 2

In the previous post I began with attempting to shape my understanding of Mental Models by looking at some of the seminal books and papers often cited. I have not yet personally arrived at any full understanding of mental models nor how to use them to explore my primary research into Design Models. In this post I want to explore some of the language and concepts that appear to be common to the study. One of the reason's for doing this is not just to understand the language from another discipline, but to be able to use the language to fix my research position in cognitive science, before discussing Indy Young's interpretation of mental models within interaction design (Young, 2008).

Again, for the casual reader of this blog, I must state that this post is simply an exercise in synthesising my research to help me understand this complex subject. This post is not a finished thesis by any means, and shouldn't be read as such. I do aim to formalise this research into a paper to underpin my first practical PhD project later on. So feel free to comment, suggest other interpretations, disagree etc.

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“‘Why do people use mental models?’ We think mental models assist human reasoning in a variety of ways. They can be used as inference engines to predict the behavior of physical systems. They can also be used to produce explanations or justifications. In addition, they can serve as mnemonic devices to facilitate remembering.”

(Williams et al, 1983, p135)

"Mental Models are simply affinity diagrams of behaviors made from ethnographic data gathered from audience representatives. (...) A mental model for a particular topic is, in essence, an affinity diagram of user behaviors."

(Young, 2008, pp2-3)

Spanning 25 years the language as to what constitutes a mental model has naturally expanded, contracted, morphed and become specialised. But is the term still describing the same cognitive concept? There appears to be be a marked difference in the use of the term at present within interaction design than the term used by Cooper, Norman and those within the cognitive science discipline. Building upon the research documented seminally in 1983, mental models at present seems to have two appearances: Indy Young's 'affinity diagram of user behaviours' (2008) and 'cognitive modelling to aid understanding'. Alan Cooper, author and chairman of interaction design company Cooper, sees things more from a more user-centred perspective akin to the cognitive scientists definition. Cooper, Norman and others understand mental models as a personal tool used by each individual to make sense of a situation, task or encounter. Cooper says,

“A person’s mental model is their own internal representation of reality – the way they think about or explain something to themselves. Mental models are deeply ingrained and are often the result of a lifetime of experience. People’s expectations about a product and the way it works are highly informed by their mental model.” (Cooper et al, 2007, p118)

Therefore to enable me to reach a clear definition of mental models, that will lead me onto my research into the Design Model, I will now explore the language found within the literature in order to resolve the Young/cognitive science interpretation of the term. I will explore Young's idea and methodology in another post.

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One of the aspects of mental models is that humans recognize structural patterns based upon previous experience or understanding of previous functionality. Mental models cannot and do not emerge fully formed, they are dynamically conceptualized from components of previous experience and knowledge. The individual selects the closest fitting components that together give them a model to understand the causality of the interaction. These components of experience/knowledge come from a prior learning process, and will themselves evolve into better components due to familiarity with the interaction over time. These components that are dynamically placed into a causal linear context are said to be cognitively "runnable". The person can conceptually "run" the causal components in their minds to envision the actual interaction, its process and its consequences. The term interaction referred to here is a general term. Interaction is a term that has an identity issue due to the different disciplines involved in defining it. Dr. Sally McMillan identified this problem nine years ago,

"while some scholars see interactivity as a function of the medium itself, others argue that interactivity resides in the perceptions of those who participate in the communication."
(McMillan, 2000)

It could be argued that the very nature of the range of definitions for interaction enriches the research surrounding its possibilities, but it can also obscure unless the exact parameters are defined to contextualise what form interactivity takes. One current industrial interpretation by Hugh Dubberly et al, of Dubberly Design Office (DDB) in San Francisco, of interaction approaches it from a systems-theory point of view (Dubberly et al, 2009). In an article posted on the DDB website he and his colleagues explore a broader systems interpretation of interaction. A paper I have previously found useful is one by Dr. Spiro Kiousis which was an explication of the term. In "" Kiousis suggests that

"interactivity is both a media and psychological factor that varies across communication technologies, communication contexts, and people's perceptions."
(Kiousis, 2002, p355)

In his explication he identifies a literature review, which by current standards a good historical benchmark, of types of interactivity. Through this he concludes that there are three common factors to interactivity from an operational point of view:

"technological structure of the media used (e.g. speed, range, timing flexibility, and sensory complexity), characteristics of communication settings (e.g. third-order dependency and social presence), and individuals’ perceptions (e.g. proximity, perceived speed, sensory activation, and telepresence)."
(Kiousis, 2002, p379)

Dubberly et al in the intervening years explore the transfer function of interaction. Looking to both Norman and Verplank Dubberly et al explore the dynamism of interactivity,

"in ‘interaction’ the precise way that ‘input affects output’ can itself change; moreover in some categories of ‘interaction’ that which is classed as ‘input’ or ‘output’ can also change, even for a continuous system"
(Dubberly et al, 2009, p3)

They refine this dynamic definition of interactivity to cover six systems: reacting, regulating, learning, balancing, managing & entertaining, and conversing (see diagram). Now I don't want to stray too far in discussing the definitions of interactivity in this post too much, I feel it is important if I am to make sense of a user's mental model being constructed to understand the interaction they are involved in. The component models that a user will "run" will naturally follow their previous experience, which in turn will informed by a form of interactivity they previously encountered. Therefore to understand a mental model dynamically conceived is contingent on also the form the interaction takes. Here is where Norman's term 'system image' twenty five years ago was coined to describe the cognitive process of how a user identifies the causality of the interaction. Each component model a person joins together to make sense of the interaction can be viewed as an 'object' with its own autonomy, its own properties are invariant and modular so that when dynamically formed as a mental model to understand one problem, that model can be disintegrated dynamically and rebuilt into a new model for a different problem using the same cognitive components. These component models of understanding are often naive, fallible, incomplete and inaccurate under quantifiable or qualitative scrutiny. They are based upon perception, learnt behaviour, deduction and previous experience of affordances. Therefore they are empirical and heuristical (Williams et al, 1983).

To understand a phenomenon the person establishes a proposition as to what needs to be achieved. This proposition is arrived at through the affordances that the phenomenon suggests. Leaving affordances to one side while I continue to nail down the roots of understanding the formation of a Mental Model. I will still be quoting from work done twenty five years ago, still cited today as seminal works, in order to then cross-examine with newer ideas as to what constitutes a mental model. Johnson-Laird was the first describe the cognitive process from a propositional reasoning point of view. Beginning with a hypothesis that people form visual images of objects and scenes by using their imaginations and experiences to dress the images, Johnson-Laird identifies that there are two psychology schools of thought upon the understanding of images: the 'imagists' and the 'propositionists'. The imagist school argue that images are a distinct form of mental representation, while the propositionist school argue that images are a secondary phenomenon, that images are a 'single underlying form of mental representation, and that images merely allows the stored experiences from previous phenomena to be more easily accessed. People who draw on this store are not adding any new information in the construction of an image. It is secondary to and underlying the main propositional representation from which an image is created. It is crucial to state that propositions in regard to mental representation are boolean, abstract and their structure are not "analogous to the structure of the objects they represent". Mental representation can therefore be broken down into three forms. The propositional representations are strings of symbols strung together to form the syntax that elucidates the mental model. The mental model is a structural analogue of the phenomenon, while the image are perceptual correlates, complimentary visualisations created from mental representations of the model from a particular point of view (Johnson-Laird, 1983). Johnson-Laird describes the distinctions between them as high-level mental processing, and ultimately the construction and manipulation of a mental model is to make it possible for a person to "reason without logic". To explain this I wish to quote Johnson-Laird's explication on propositional reasoning before I end this post.

“Philosophers have generally taken propositions to be conscious objects of thought – those entities that we entertain, believe, think, doubt, etc., and that are expressed by sentences (…). Since I am concerned, not with the nature of the ‘machine code’ of the brain (…), but with the types of higher level of representation, I propose to revert henceforth to the traditional philosophical terminology: a propositional representation is a mental representation of a verbally expressible proposition. (…) Propositions can refer to the world. Human beings, of course, do not apprehend the world directly; they possess only an internal representation of it, because perception is the construction of a model of the world. They are unable to compare this perceptual representation directly with the world – it is their world (…). Propositions can also refer to the imaginary or hypothetical worlds. One proposition may be false of such a world given that others are true of it. Human beings can evidently construct mental models by acts of imagination and can relate propositions to such models. (…) Unlike a propositional representation, a mental model does not have an arbitrarily chosen syntactic structure, but one that plays a direct representational role since it is analogous to the structure of the corresponding state of affairs in the world – as we perceive or conceive it. However, the analogical structure of mental models can vary considerably. (…) A characteristic difference in the contents of mental models, images, and propositional representations, concerns their specificity. Models, like images, are highly specific – a characteristic which has often drawn comment from philosophers. (…) Hence, if you reason on the basis of a model or image, you must take pains to ensure that your conclusion goes beyond the specific instance you considered" (1983, p155-158).

I will end this long post here as I wish to take another approach to understanding a mental model in my next posts. Again let me leave you, the reader, with my purpose for this post. It isn't a completed thesis by any means, merely a representation of the process I am taking to synthesize and understand a very complex subject. My interpretations, assumptions and understanding so far may be wholly wrong, naive or even accurate. This post in its current state should merely be read with my intentions in mind. Any comments, suggestions etc. would greatly be appreciated, especially if you are from a cognitive science discipline.

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References

DUBBERLY, H., HAQUE, U., and PANGARO, P. (2009) What is interaction? Are there different types? Dubberly Design Office [online], [Accessed 15 March 2009], (pp.1-12) Available from World Wide Web: http://www.dubberly.com/articles/what-is-interaction.html.

KIOUSIS, S. (2002) Interactivity: a concept explication. New Media & Society, SAGE Publications, Vol4(3):355–383

McMILLAN, S.J. (2000) ‘Interactivity is in the Eye of the Beholder. Function, Perception, Involvement, and Attitude Toward Web Sites’, in M.A. Shaver (ed.) Proceedings of the 2000 Conference of the American Academy of Advertising, pp. 71–8. East Lansing, MI: Michigan State University.

See Design Model - statement for a full list of references this post cites beyond those indicated above.

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Mental Model Literature Review - Part 1

In this post I not only wish to contextually review the literature on mental models but also to define the use of the term that will be central to my first practical PhD project. Mental Models is unfortunately a term that has had its meaning diluted by non-cognitive science practioners such as Indi Young (more on this later). Therefore I will be exploring Mental Models firstly from a cognitive science perspective in order then to draw parallels and influences into Interaction Design. This post is not a defined thesis on my part but an attempt to draw together the essence of mental models. There will be theoretical holes in what I will post, so feel free to point them out. Look on what follows as simply my first attempt to stitch together my understanding of a very complex cognitive science discourse, from a discipline that is not my own. I will continue this literature review across several posts with the aim of refining my understanding.

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To begin with I am going to quote psychologist Kenneth Craik (1914-1945) from his 1943 book The Nature of Explanation. Craik is cited by cognitive scientist Johnson-Laird in his 1983 seminal work Mental Models as proposing the first modern hypothesis on humans being processors of information in order to understand phenomena.

”If the organism carries a “small-scale model” of external reality and of its own possible actions within its head, it is able to try out various alternatives, conclude which is the best of them, react to future situations before they arise, utilise knowledge of past events in dealing with present and future, and in every way to react in a much fuller, safer, and more competent manner to emergencies which face it.” (Craik, 1943, p57)

This statement was to open up a whole new area of research within the already new scientific discipline of cognitive science. By 1983 Mental Models research had two seminal works that explored this concept. Johnson-Laird proposed that the human mind uses propositional reasoning instead of reductive mathematical logic to understand phenomena. Gentner and Stevens, in their edited collection of papers, also entitled Mental Models, present a diverse range of views, including an early paper by Dr Donald Norman who here begins the discourse upon the Design Model. If Johnson-Laird proposes propositional reasoning, then Gentner and Stevens' book explores the structure of knowledge representations specific to different domains of application. Johnson-Laird states in introducing his book,

"The psychological core of understanding, I shall assume, consists in your having a 'working model' of the phenomenon in your mind. (…) you have a mental representation that serves as a model of an entity (…) A model has, in Craik’s phrase, a similar ‘relation-structure’ to the process it models, and hence it can be useful explanatorily; a simulation merely mimics the phenomenon without relying on a similar underlying relation-structure. Many of the models in people’s minds are little more than high-grade simulations, but they are none the less useful provided that the picture is accurate; all representations of physical phenomena necessarily contain an element of simulation." (Johnson-Laird, 1983, p2/4)

The importance here is that a 'relation-structure' the functionality of a cognitive conceptual model. To propose an explanation on how a phenomenom works, a model that is constructed by a person is NOT improved by them also trying to understand the specific context it is encountered in. The specific context is not transferable to another context but the mental model will be. The model will not be complete each time it is applied, but in Chomsky's term 'explanatory adequate'. To Johnson-Laird because a mental model is constructed by mental logic, mental logic has six main problems. Inference, formulation and deduction all are contributory to the empirical nature of mental logic. He lists the problems as (pp39-40):

1. People make fallacious inferences.


2. Which logic, or logics, are to be found in the mind?


3. How is logic formulated in the mind?


4. How does a system of logic arise in the mind?


5. What evidence there is about the psychology of reasoning suggests that deductions are not immune to the content of the premises.


6. People follow extra-logical heuristics when they make spontaneous inferences.

People's powers of deriving a reasoned solution based upon a premise they have, or from precedence is strongly affected by their own cognition that is deceptive. Mental models, although helpful to understanding a phenomenon, are inherently 'incomplete' (Johnson-Laird, 1983)(Norman, 1983), 'doubtful validity' (Norman, 1983), 'fragmentary' (Norman, 1998), 'dynamically constructed' (Preece et al, 1995), and 'not always correct' (Gentner and Gentner, 1983). As Johnson-Laird argues, the formulation of a mental model to understand a phenomenon is 'propositional reasoning' on behalf of each individual. Norman explains this in more accessible terms:

"The power of mental models is that they let you figure out what would happen in novel situations. Or, if you are actually doing the task and there is a problem, they let you figure out what is happening. If the model is wrong you will be wrong too." (Norman, 1998, p71)

If the person's proposition regarding the causality, relationships and mechanisms within a phenomenon encountered is poorly appreciated then their understanding of that phenomenon will not work. But an incomplete proposition that does capture the behaviour of that phenomenon, that for them represents the causality and mechanisms of that phenomenon based upon previous experiences, or from fragmentary experiences of aspects of similar phenomena, can arrive at an 'explanatory adequate' mental model. This is why Norman describes the human mental process as "unscientific" that supports Johnson-Laird's argument that humans do not use reductive mathematical logic as the brain is a computer. In their book The Embodied Mind Varelo et al refer to phenomenologist Edmund Husserl (1859-1938) to contextualise human cognition from a different perspective, where a human's 'sensorimotor capacities' is enabling enough to successfully interact within an environment with the phenomenon. According to their thesis Husserl claimed

"that to understand cognition, we cannot take the world naively but must see it instead as having the mark of our own structure. He also took the second step, at least partially, in realizing that that structure (the first step) was something that he was cognizing with his own mind.(…)He explicitly focused on the experience of consciousness in what he called the “lived-world.” The lived world is not the naive, theoretical conception of the world found in the natural attitude. It is, rather, the everyday social world, in which theory is always directed toward some practical end. Husserl argued that all reflection, all theoretical activity, including science, presupposes the life-world as a background. The task of the phenomenologist now became the analysis of the essential relation between consciousness, experience, and this life-world.” (Varelo et al, 1996, pp16-17)

For each person to construct a mental model of a phenomenon based upon proposition reasoning, entails them cognizing the problem from their previous experiences built into a appropriate functional model (Preece et al, 1995) developed from existing knowledge of a similar context. As a mental model is a dynamic conceptual tool to solve a problem within a phenomena, they can be be said to be drawn from Husserl's concept of the 'lived-world'.

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References

See Design Model - statement for list of references cited in this post.

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Design Model - Notes in Progress

My starting point in researching the concept of the design model will begin with defining exactly what that model is. My starting point will be balanced between three writers on the subject: Don Norman, Alan Cooper and Richard Young. I will in this post clarify what a design model is and what its purpose is. I will also discuss the difference between a design model and the interface design itself.

Defining the Design Model

To begin with the design model it is crucial that the varying terminology used by the writers is explained and synthesised into one term. Before I continue with defining this particular model I think it is important to mention the variant terms used since 1983 in order to synthesise into one term. User's conceptual model, represented model and designer's model are all terms that point to the same cognitive tool. The cognitive science research into mental models emerged into the literature in 1983 (more about this in a separate post). Dr. Donald Norman, a cognitive scientist who transitioned across disciplines into human-computer interaction and interaction design, began to develop his design model research at this time. In Mental Models edited by Gentner and Stevens, one of the two 1983 seminal books on this subject, Norman wrote about the System Image.

Term One: The System Image

In his chapter Some Observations on Mental Models Norman proposes that the conceptual model a person makes about an interactive system should have, in an ideal world, its design based around that model.

"This conceptual model should govern the entire human interface with the system, so that the image of that system seen by the user is consistent, cohesive, and intelligible." (Norman, 1983, p13)

This image, the system image is Norman's early separation of the conceptual model for representing design decisions from a user's mental model of how an interactive system works. Within conceptual models images, according to Johnson-Laird, are "perceptual correlates of models from a particular point of view" (Johnson-Laird, 1983, p165). Johnson-Laird, in his 1983 book Mental Models tells us that “many people report that they can use their imaginations to form a visual image of an object or a scene." (ibid, p147) This 'mental model' is a high-level cognitive process, a mental representation of the functionality and causality of an interaction that is constructed by an individual person. An 'image' is one of three forms of mental representation; the other two being a mental model and a propositional representation. To keep this post focused upon the design model I will keep this brief. If a mental model is a person's 'structural analogue' for understanding an interaction, then an 'image' is the interface designer's conceptualization of how to facilitate a person's success from that interaction. It is dangerous to infer that a 'system image' is the visual interface design - the graphic design. That is a feature of the 'system image' but not its whole.

The 'system' is a key component of this term. The interactive system of the product is based upon algorithmic principles and functions according to the coded commands of that system. People do not, or will not, understand its complexity before using the interactive product. Their interest is using the product to solicit a successful conclusion to a particular goal (whatever that can be defined as). The interface between the task and the goal, the user and the conclusion, is conceptualized by the designers. It is in the interest of the person using the interactive product to feel satisfied that they have successfully achieved what they set out to achieve. Therefore a interaction designer needs to conceptualize a method to facilitate the easiest way for the user to gain their goal. This is achieved by taking into account the user experience of the product, the user's behaviour (suggested by their mental models of using the product - see separate post), human factors, branding, semiotics, accessibility and usability, and information flow. How a designer processes these design parameters, conceptualizing them into a successful design is where a design model comes cognitively into its own.

Term Two: UCM - User's Conceptual Model

It was in 1983 that Norman and Young began to identify this design modelling as part of the cognitive science discourse. Norman developed the 'system image' idea further over the next decade until Cooper defined it within interaction design discourse. Before I proceed to Cooper's 'represented model' I first want to stay in 1983 and mention Richard Young's discussion on what Norman is raising. Young doesn't deal directly with the designer's conceptualization, but in discussing the then term UCM (user's conceptual model) he does also discuss the designer. Young explores the same trinity of cognitive conceptualization, that of the user's modelling of the system, how the system itself works and how to facilitate the interface between them. His discourse is a cogitation between the differing aims of a cognitive psychologist and a designer towards observing and helping the user. He is unclear if the psychologist and designer should share the same conceptual model as the user due to the differing requirements from the model. These differing requirements from the UCM, Young suggests, could possibly shape it in different ways, depending upon who it is.

Although the UCM doesn't live long as a term within my literature review, in 1983 Young postulates a point that both Norman and Cooper develop over the next 20 years. Young does state that a designer could, or should, share the model a user has of an interactive product. But to facilitate the product's successful use, the designer needs to incorporate assumptions on how a user will engage with it (based upon the user's mental model) and use it. He remarks that this conceptual model the designer would use will be cruder than the model that explains the implementation of the system. This model, constructed by the designer, may appear to invalidate aspects of the model that more closely correlates with the interactive system's actual implementation. This is where the design model, to me begins to become defined. Norman's writing and Young's, both included in the same seminal edited book on Mental Models from 1983, begin this discourse that, I suggest, develops over the next twenty five years through HCI and interaction design through practical work. I am suggesting that the design model is theoretically under-examined within both cognitive science and the design disciplines, whereas the research into user's mental models has progressed. The research into a design model is a subset of mental models but, I believe, could re-focus the application of visual communication within interaction design (Young, 1983, p35).

My final task within this post is to bring the design model discourse up to date. This is where I will turn my attention to Cooper's term of the 'represented model'.

Term Three: Represented Model

Alan Cooper, of interaction design company Cooper, in his 2007 book About Face 3 discusses Norman's concept, referring to it more specifically as a 'designer's model rather than design model. With a background emerging out of software design Cooper et al Cooper draws upon the terminology of that discipline and prefers to call this cognitive model a designer'sRepresented Model. Within software development a "program's represented model can (and often should) be quite different from the actual processing structure of the program" (Cooper et al, 2007, p29). The processing structure referred to is the the third cognitive model of the actual implementation and processing of the system. In interaction design for software the "ability to represent the computer’s functioning independent of its true actions (…) allows a clever designer to hide some of the more unsavoury facts of how the software is really getting the job done" (ibid, 2007, p29) It is within this cognitive abstraction that the "disconnection between what is implemented and what is offered as an explanation" occurs, and the represented model is choices that a designer makes based upon understanding both the system's functioning (implementation model) and the user's understanding of how they perceive it to work (mental model).

It is suspended between two different cognitive models that the represented model exists. A way for the designer to translate the cold, algorithmic functionality of an interactive system into a warmer experience, designed around a user's understanding of how they perceive the system works. Therefore a designer needs to understand and communicate through information architecture, visual and experience design, an interface that is conceived through a designer's cognitive model derived by understanding both a model for implementation and a model of how a user cognitively understands the process. This mental model is based each individual user's own experience and what they have learnt. These will raise or lower their expectations of how the interactive system works, according to their own cognitive ability (more on this in another post). The closer a designer gets to the general expectations of the users, the consensus is, the easier the interaction process will be, "One of the most important goals of the designer should be to make the represented model match the mental model of users as closely as possible" (ibid, 2007, p70). To do this a designer must have the research that formally records user expectations, their attitude, their perceived expectation and influences upon that expectation, and cognitive factors that contribute to the complexity of the model. "Intelligent people always learn better when they understand cause and effect, so you must give them an understanding of why things work as they do" Cooper et al suggests; by following the user's model "it will provide the understanding the user needs without forcing him to figure out the implementation model" (ibid, 2007, p46). The final conclusion from Cooper's discussion of represented model is a sobering idea about the user, "Everything a user does is something he or she considers to be valid and reasonable. Most people don’t like to admit to mistakes in their own minds, so the program shouldn’t contradict this mindset in its interactions with users" (ibid, 2007, p336).

A final note on why I prefer to use Norman's term design model is that there is a subtle difference between Cooper and Norman's two cognitive models. Although both are discussing the same cognitive process, for me, the term design model is a clearer term to use when discussing how to conceptualize an interactive system for a user. As the designer ultimately must communicate through the interactive system itself of how it works to a user, the designer must design the user interface so it is closer to how the user believes the interactive system works. I will in two further posts explore the user's mental model and methodologies for understanding them, before expanding upon the design model.

This post is not my definitive thesis upon this subject, but merely my current understanding and synthesis. I will be revising my views over the coming weeks in light of posting. Any comments would be helpful for me in that process.

References:

COOPER, A., REIMAN, R. and CRONIN, D. (2007) About Face 3: The Essentials of Interaction Design. Indianapolis: Wiley Publishing Inc.

NORMAN, D.A. (1983) Some observations on Mental Models. In D. GENTNER, and A.L. STEVENS, eds. Mental Models. Lawrence Erlbaum Associates Inc. pp7-14

NORMAN, D.A. (1998) The Design of Everyday Things. MIT Press

YOUNG, R.M. (1983) Surrogates and Mappings: Two Kinds of Conceptual Models for Interactive Devices. In D. GENTNER, and A.L. STEVENS, eds. Mental Models. Lawrence Erlbaum Associates Inc. pp35-52

Design Model - statement

Literature Review

As my literature review has come to its current end on Mental Models I will now, over the next week, use this blog and my PhD Project Blog as a sounding board to synthesise all the cognitive science research I've engaged in since February. The forthcoming posts will hopefully inform a paper that will theoretically under-pin my first practical design project as part of my PhD. Please feel free to comment and make suggestions as I shape my understanding of Mental Models from a visual communication perspective. The main cognitive literature I have read and will use can be found at the bottom of this post. I will list the embodied cognition literature in a separate post.

Design Model

My desire is to creatively experiment through interactive design prototyping what Donald Norman describes as the Design Model. This is a designer's cognitive model of how an interactive product's functionality can be visually, spatially and temporally represented so that a user can operate the interactive product. The Design Model, a conceptual visualization on the designer's part, helps solicit the correct design choices to allow a user to use and experience the interactive product easily. The interactivity of the product is architectured in such a way to be implemented through coding and algorithms. This mechanistic programming of interaction may be HOW the product works, but the user won't understand how a product works from an implementation perspective.

User's Cognition

Users understand that an interactive product has to be experienced, and that causality affords decision-making as to how to use a product. Through cause and effect, prior experience and varying degrees of cognitive problem-solving, user's individually discover their method for understanding how to use the product. User's may all be able to use the same interactive product, but if asked HOW it works they will not be able to explain it based upon how implementally it was coded. They each will approximate a model of HOW they understand it works. As the cognitive science literature points out this user model will probably be fallacious, inferred, deduced, inaccurate and contradictory; but by constructing the cognitive model the user reasons how to use the interactive product. This user cognitive model is referred to as a user's Mental Model.

Objective

In my posts I will unpack these cognitive models in order to understand how to improve understanding of the Design Model in order to add to the sparse literature within interaction design and visual communication disciplines. Firstly I will process the cognitive science literature on mental models to ground myself in understanding HOW a user processes causal information. I will then post, as an alternative cognitive perspective, on how embodied cognition may view the same subject. Throughout I will be expanding upon what has been written about the Design Model.

Terminology

To end I just need to clarify my use of the terminology regarding Design Model. As with any subject that sits across disciplines people arrive at the same or similar concepts using different terminology. In trying to avoid a taxonomic history I will keep things simple. Norman uses the term design model (Norman, 1998) whilst interaction designer Alan Cooper calls it a representational model (Cooper et al, 2008). Cooper also refers to Norman's term as a designer's model. An earlier term from the Eighties used in the context of a designer was a "UCM" or user's conceptual model (Young, 1983).

To keep things simple within my research I will now only use Norman's term Design Model. I choose Norman's term as it is the simplest term to describe what all three describe, and a term that is devoid of personal individual ownership.

References:

COOPER, A., REIMAN, R. and CRONIN, D. (2007) About Face 3: The Essentials of Interaction Design. Indianapolis: Wiley Publishing Inc.

CRAIK, K.J.W. (1943) The Nature of Explanation. Cambridge: Cambridge University Press

de KLEER, J. and SEELY BROWN, J. (1983) Assumptions and Ambiguities in Mechanistic Mental Models. In D. GENTNER, and A.L. STEVENS, eds. Mental Models. Lawrence Erlbaum Associates Inc. pp155-190

GENTNER, D. and STEVENS, A.L. (1983) Introduction. In D. GENTNER, and A.L. STEVENS, eds. Mental Models. Lawrence Erlbaum Associates Inc. pp1-6

GENTNER, D. & GENTNER D.R. (1983) Flowing Waters or Teeming Crowds: Mental Models of Electricity. In D. GENTNER, and A.L. STEVENS, eds. Mental Models. Lawrence Erlbaum Associates Inc. pp99-129

JOHNSON-LAIRD, P.N. (1983) Mental Models. Cambridge: University Press.

MARR, D. (1982) Vision: A Computational Investigation into the Human Representation and Processing of Visual Information. New York: W.H. Freeman and Company.

NORMAN, D.A. (1983) Some observations on Mental Models. In D. GENTNER, and A.L. STEVENS, eds. Mental Models. Lawrence Erlbaum Associates Inc. pp7-14

NORMAN, D.A. (1998) The Design of Everyday Things. MIT Press

PREECE, J., ROGERS, Y., SHARP, H., BENYON, D., HOLLAND, S., & CAREY, T. (1995) Human-Computer Interaction. Addison-Wesley Publishing Company

PREECE, J., ROGERS, Y. & SHARP, H. (2002) Interaction Design: Beyond Human-Computer Interaction. John Wiley & Sons, Inc

SPOOL, J. (2008) SpoolCast: Reviewing Mental Models with Indi Young [online]. [Accessed 13 May 2008]. Available from World Wide Web: [Podcast]

VARELO,J., THOMPSON, E. and ROSCH,E. (1996) The Embodied Mind: Cognitive Science and Human Experience. Cambridge, Mass.: MIT Press

WILLIAMS, M.D., HOLLAN, J.D. and STEVENS, A.L. (1983) Human Reasoning About a Simple Physical System. In D. GENTNER, and A.L. STEVENS, eds. Mental Models. Lawrence Erlbaum Associates Inc. pp131-153

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Paper abstract accepted for International Design Research Conference in South Korea (revised post)

The abstract for my paper "Interaction Design: Where's the Graphic Designer in the Graphical User Interface?" has been accepted for entry into IASDR 2009 in Seoul in October. The International Design Research conference brings together "top design researchers and practioners to build and advance knowledge in the field of Design."

I've just uploaded my full paper for the next selection phase so I'll post more information as soon as I know. The next phase will be announced in August.