Dues cadires de rodes vistes des de darrera

Mental models concept has been described in several disciplines, with its origins often being attributed to the field of psychology and the work of Craik (1943), or alternatively to the introduction of schemas by Bartlett (1932). Subsequently the fields of natural resource management (Jones et al., 2011), cognitive psychology, system dynamics, psychology, human-machine and human-computer interaction, risk perception, and communication have made use of the concept (Doyle and Ford, 1998). The variety of disciplines have used the notion for a multitude of purposes including scripts for understanding routine activities (Bower and Morrow, 1990; Schank and Abelson, 1977), situation models for understanding text (Van Dijk and Kintsch, 1983), causal scenarios or stories to aid in making causal attributions or judging likelihood (Kahneman and Tversky, 1982; Read, 1987; Tversky and Kahneman, 1973), scenarios to enable judgmental forecasting (Jungermann and Thüring, 1987), schemas for perceiving and remembering information about people (Fiske and Taylor, 1991), imagery that allows objects not physically present to be

scanned and mentally manipulated (Kosslyn, 1990), and problem

representations to help structure and manipulate information during problem solving (Greeno, 1977), as discussed by Doyle & Ford (1998).The authors also explain that while it is possible to draw some sort of boundaries around the field of mental models research, the task is made more difficult by the variety

52

of terms that are used by academics: mental picture (Alexander, 1964), mental representation (Pennington, 1987), folk theory (McCloskey, 1983a), naive problem representation (Larkin, 1983), intuitive theory (McCloskey, 1983b), implicit theory (Neisser, 1987), knowledge map (Howard, 1989), idealised cognitive model (Lakoff, 1999), conceptual model (Young, 1983), internal model (Veldhuyzen and Stassen, 1977), cognitive structure

(Shavelson, 1972) and knowledge structure (Means and Voss, 1985). Quite naturally, this extensive use has rendered a plethora of definitions of mental models (see Table 2-7 for a summary) and has created a situation where the term could mean “all things to all people” (Wilson and Rutherford, 1989, p. 630) and be too vague for any tangible benefit.

Definition Reference

“[Mental models are] intuitive generalizations from observations of real world events”

(Meadows et al., 1974, pp. 4–5)

“Mental models ... contain the ideas, opinions, assumptions, etc. with respect to a policy problem and related issues”

(Vennix, 1990, p. 16)

“”Mental Models” are deeply ingrained

assumptions generalizations, or even pictures or images that influence how we understand the world and how we take action. Very often, we are not consciously aware of our mental models or the effects they have on our behaviour”

53

“It is useful to think of mental models as a dynamic pattern of connections compromising a core

network of “familiar” facts and concepts, and a vast matrix of potential connections that are stimulated by thinking and the flow of conversation”

(Morecroft, 1992, p. 7)

...mental models are multifaceted, including

distinguishable sub-models focused on ends (goals), means (strategies, tactics, policy levers) and

connections between them (the means/ends model).

(Richardson et al., 1994 as seen in Doyle & Ford, 1998)

“In systems dynamics, the term mental model stresses the implicit causal maps of a system we hold, our beliefs about the network of causes and effects that describe how a system operates, the boundary of the model (the exogenous variables) and the time horizon we consider relevant – our framing or articulation of a problem.”

(Sterman, 1994, p. 294)

“Mental models are some sort of psychological construction with an intended representational content. Mental models ... are usually expressed by a set of sentences in ordinary language, describing both the interactions among the elements within the system and their external influences”

(Vázquez et al., 1996, p. 25)

54

“A mental model can be defined as a

representation of a body of knowledge – either a long-term or short-term that meets the following conditions: 1. Its structure corresponds to the structure of the situation that it represents. 2. It can consist of elements corresponding only to

perceptible entities, in which case it may be realized as an image, perceptual or imaginary. 3. Unlike other proposed forms of representation, it does not contain variables ... In place of a variable ... a model employs tokens.”

(Johnson-Laird, 1989, p. 488)

[knowledge about] “how a device works in terms of its internal structures and processes”

(Kieras and Bovair, 1984, p. 255)

“Organized structures consisting of objects and their relationships”

(Staggers and Norcio, 1993, p. 590)

“abstract concepts that ... represent a person’s knowledge of a decision problem”

(Coury et al., 1992, p. 673)

“Mental models are the mechanisms whereby humans are able to generate descriptions of system purpose and form, explanations of system

functioning and observed system states, and predictions of future system states.”

(Rouse and Morris, 1986, p. 351)

55

“by a mental model we mean a person’s

understanding of the environment. It can represent different states of the problem and the causal relationships among states.”

(Shih and Alessi, 1994, p. 157)

“mental model of a dynamic system is a relatively enduring and accessible, but limited, internal conceptual representation of an external system whose structure maintains the perceived structure of that system.”

(Doyle and Ford, 1998, p. 17)

“people at work hold in their minds a

representation of the systems with which they are working, and upon which they draw to assist their understanding and operation of those systems”

(Wilson, 2006, p. 800)

Table 2-7 comparison of mental models definitions

At this stage, Doyle and Ford’s (1998) definition (see above) is adopted to provide a common starting point, due to the authors extensive research of previous work on the definition of the term as well as the alignment of the discussion of the term’s components (‘relatively enduring’, ‘limited’, ‘conceptual’, ‘external system’ etc.) that reflect this author’s view of the factors at play regarding the current domain (for a further description on the components of the discussion, see (Doyle and Ford, 1998)). However, since the existence of mental models within the observed situation between users of home heating controls and the system they control is assumed to be slightly different in certain aspects, mainly as that interaction is more likely to display a Human-Computer Interaction (HCI) or human factors approach to mental models; other definitions may be used to address specific phenomena that are deemed relevant to this research field.

56