3.3    Models and Modeling: A Clarification of Concepts

The concepts of model and modeling have already been analyzed in-depth by a number of competent researchers, and a timely question may be why yet another discussion is insisted upon. One reason is that the two different worldviews have different implications for models and modeling. Another reason is to make sure that the reader at least roughly understands the concepts as intended in this thesis.

3.3.1 What is meant by a model?

Literature is rife with definitions of the term model (abundant, would some say). A representative sample include the following (italics added):
"A model is a purposeful representation." (Starfield, Smith and Bleloch, 1990)

"A model is a structure that a system can use to simulate or anticipate the behavior of something else." (Høyte, 1992:18)

"A model is an abstraction externalized in a language." (Krogstie, 1995:476)

"A model is an abstraction of something for the purpose of understanding it before building it." (Rumbaugh et al., 1991:15)

"A model is the explicit expression of one's understanding of a system or situation. 70; A model is a representation of something else." (ISO/ANSI, 1994:11)

The most striking common denominator (explicitly or implicitly stated) is that a model is something that represents something else. There is a perceived relationship between two phenomena, in which one of them possesses some undefined quality that makes the observer categorize it as a model of the other phenomenon. The prototype of what is not a model of a given phenomenon is in a sense the phenomenon itself.

Based on this wide characterization of models, the relationships between models, the modeled UoD and the modeler will be discussed next.

The 'model' concept

Figure 3.2 illustrates the characteristics of models considered to be most relevant in this thesis. The main elements are expressions E, impressions I and the modelers M. Expressions are physical artifacts or objects that are perceived to exist in reality. An oil platform and a sheet of paper with ink on it are examples of expressions. An impression is the meaning that an actor associates with an expression. The modeler is an actor that is capable of interpreting expressions (i.e., attribute meaning to expressions). Expressions and impressions concern either the UoD (or world, indicated by subscript w) or the model (subscript m).
Figure 3.2: The concept 'model' as a representation of a world

Figure 3.2 may be read as follows: Ew is physical reality that is perceived to exist (in an organization, Ew refers to the material embodiment of the externalized, organizational reality). Iw is how the modeler M interprets Ew, i.e., the meaning attributed to organizational reality. Im is a deliberate, alternative representation made by M of Iw, and Em is the expression being a manifestation of Im, created by M. The pair (Em, Im) is said to be a model of (Ew, Iw). Hence, a model is a compound phenomenon (Em, Im) playing the role depicted in figure 3.2.
 

In figure 3.2, the real world phenomenon that is modeled is exemplified by an oil platform. It may equally well be a more intangible construction, e.g., a dialogue between two colleagues. The real world expression of such a dialogue is the sounds and gestures, the impression is the meaning the modeler attributes to these waves and gestures (e.g., interpreting it as a quarrel or a flirt).
 

Models as boundary objects

Recalling the theories from section 3.2, a model can be considered an explicit representation of aspects of the perspective developed within a community of knowing (by the modelers). The modeler M in is either an individual or a group of social actors, comprising a community of knowing. With respect to other communities, the model has the potential of becoming a boundary object that can be used to inform others about the unique knowledge developed within a community.

Figure 3.2 is a valid model of models from both an objectivist and constructivist point of view. Still, the nature of expressions and impressions differ substantially based on worldview taken. From an objectivist point of view, the meaning of Ew is given objectively as Iw and can be experienced directly. Likewise, the meaning of Em is given as Im, based on a formally defined syntax and semantics of the modeling language. Hence, one may develop general criteria for estimating the goodness (the quality) of the representation of Iw as Im.

From a constructivist point of view, the meaning of Ew is subjective, but more or less subject to closure following from social construction. The meaning Iw is not inherent to Ew, but relative to a perspective held within the community. The meaning Im of Em is neither objectively given, and both Iw and Im may change over time (from a hermeneutic point of view). Hence, the goodness of the representation of Iw by Im depends on the relationship between the horizons of the model creator and interpreter (as also claimed by Klein and Lyytinen, 1992:214).

3.3.2 What is meant by modeling?

Having discussed the notion of a model in detail, the attention is now turned to modeling. A general model of modeling is presented before discussing it in terms of perspective making and perspective taking.

The 'modeling' concept

Figure 3.3 illustrates the process of modeling corresponding to the outline of a model as presented in figure 3.2.
Figure 3.3: The process of modeling

Figure 3.3 includes the four concepts Ew, Iw, Im and Em and actors from Figure 3.2. The process of model creation is depicted from left to right, while the process of model interpretation goes from right to left. The loop at the far right can be considered distribution of the model expression as the model creators and the model interpreters may not be the same.

Modeling is seen as embracing three major activities: Sense-making, representation and manifestation. Both model creation and model interpretation involve these three activities. Model creation is described first:

Sense-making Ew => Iw: The model creator attempts to interpret and make sense of the UoD. The sense-making process may not necessarily involve a physical reality (Ew may play a minor role when creating models of UoDs constructed through imagination and not grounded experientially, Lakoff and Johnson, 1980:193).

Representation Iw => Im: The model creator deliberately associates concepts perceived to be a part of the UoD with selected concepts understood to be a part of what might be called a modeling language. Representation is not necessarily direct mapping.

Manifestation Im => Em: The model creator externalizes the representation using a chosen medium, e.g., draws the model on a sheet of paper. The medium might be audio, video, paper, digital computers, etc.

The three activities can be carried out simultaneously. Sense-making, representation and manifestation are integrated activities in the sense that the modeler improves her understanding of the domain by making preliminary and alternative representations and sketches of a model, tacking back and forth between the activities.

The three activities above constitute what is considered the creative side of modeling in this thesis -- to make sense of a domain, deliberately represent it in some way and express the representation using some medium. The three following activities correspond to the use of models, the interpretive side of modeling:

Sense-making Em => Im: The model interpreter attempts to make sense of the model expression by attributing meaning to the model symbols.

Representation Im => Iw: The model interpreter associates something with the model impression, seeking to imagine what the original modeler created a model of, i.e., her UoD.

Manifestation Iw => Ew: The model interpreter might use the understanding gained from interpreting the model, e.g., to construct an artifact. In this sense, manifestation becomes action, externalizing the local reality in speech or deed.

Note that the model expression is just as real as the world expression and that model creation and model interpretation in a sense are symmetric. Hence, one may question what is the difference between the two processes? In principle, the most obvious difference is the purpose -- the deliberate representation of Iw by Im, creating the artifact Em in the first place. Hence, what is world (UoD) and what is model is decided by purpose. In practice (as also seen from several of the definitions of model on page ), abstraction is an essential trait of models.

Modeling as perspective making and perspective taking

Modeling (including both model creation and interpretation) can be seen as a process of perspective making and perspective taking. Model creation is dominantly perspective making, even if making sense of the domain that is to be modeled also may require taking the perspectives of other communities of knowing. Model interpretation is perspective taking when it involves the interpretation of the explicit representation of another community's knowledge of a given domain.

As for the model concept in section , the modeling concept is valid independently of worldview. However, the perceived challenges of the modeling process (both model creation and interpretation) differ substantially according to the chosen worldview.

From an objectivist point of view, the following can be assumed to hold:

From a constructivist point of view, the following can be assumed to hold: From an objectivist point of view, modeling is a matter of creating correct and accurate models and modeling languages, as these are sufficient for conveying the meaning intended to be represented in a model. From a constructivist point of view, the actors and the processes of model creation and model interpretation are the most influential on the meaning attributed to the models.