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2.2 Model Building and Learning

2.2.3 Empirical Studies

The second category of literature contains empirical studies of decision maker learn-

ing from involvement in simulation model building. Although the studies discussed

are useful in understanding learning from the involvement of building simulation

models; these in general do not directly compare quantitative simulation model

building to model (re)use; they are either qualitative model building (Shields, 2001,

2002) or based on a full modelling interventions including substantial experimenta-

tion (Thomke, 1998; Rouwette et al., 2010). Moreover, none of the studies to be

discussed is focussed on discrete-event simulation. This section examines the sup-

section.

Before reviewing this literature in detail it is worth pointing out that a number of

experimental SD studies have compared the effect of the level of model transparency

on learning without including participants in the building of the model. Rouwette

et al. (2004) conduct a literature survey of the factors influencing individual decision

maker rationality when using SD simulation models. They find four studies that

support the conceptual discussion regarding transparency aiding learning. These

experiments provide transparency via introduction to the conceptual model (Young

et al., 1992), teaching of SD and the model (Gr¨oßler, 1998; Gr¨oßler et al., 2000) or

providing details of the conceptual model as the participants struggle with the model

(O’Neill, 1992). These studies indirectly support the belief that model building aids

learning through increased transparency.

Turning to the literature that explores learning from involvement in the mod-

elling process, the most recent example is an extensive study into attitude change

conducted by Rouwette et al. (2010). They develop and test a conceptual model for

attitude change in group model building (GMB) interventions based on the Theory

of Planned Behaviour (Ajzen, 1991) and theories of persuasion (Petty and Cacioppo,

1986; Chaiken et al., 1989). These theories are discussed in detail in Section 3.3.

Rouwette et al. use data from seven SD field studies they conduct for different

clients; for example, a housing association, an oil company and the ministry of

transport. The study uses a pre-test post-test (i.e. before and after the intervention)

design making use of content analysis (for project reports), questionnaires and post-

test interviews. In total 14 variables are measured across three areas: context,

mechanism and outcome. A full list of these along with an explanation can be

found in Rouwette et al. (2010); a more detailed account can be found in Rouwette

(2003). Here only an overview of the most relevant findings is given.

of persuasion: the elaboration likelihood model (Petty and Cacioppo, 1986) and the

heuristic-systematic model (Chaiken et al., 1989). Rouwette et al. measure the vari-

ables theorised to be the most important for systematic processing and evaluation of

information: argument quality, assessed by questionnaire and interview, and ability

to process information. These are assessed by a questionnaire taken from Vennix

et al. (1993) and Rouwette et al. (1998). Outcomes contained seven variables based

on another social psychology theory widely used to predict and explain individuals

intentions and behaviour called the Theory of Planned Behaviour (Ajzen, 1991).

This is reviewed in detail in Section 3.3. For now it enough to say that Rouwette

et al measure a change in participant’s attitudes towards options to improve sys-

tem performance. These attitudes are related to participant’s views about the other

members of the groups and the perceived control they have over the implementation

of the options they are investigating.

Rouwette et al. (2010) have three findings that are relevant to learning. Firstly,

they find that ability to process information has only a weak relation to pos-test atti-

tude; and no relationship with either the participant’s views of other members of the

group or the perceived control they have over implementing the options. Secondly,

the intervention appears to have no effect on the perceived control participants have

over implementing the options. Rouwette et al. remark that this is surprising as

most SD practioners would expect simulation to identify control variables with a

large impact on the problem. Lastly, they find that the participants often could not

identify learning outcomes in the study - even if their attitude measures showed sub-

stantial difference from pre to post-test. This agrees with the general view of social

psychologists that individuals struggle to understand their own learning (Nisbett

and Wilson, 1977). Rouwette et al. recommend that participants in a group model

building study are asked to list three options to improve performance before and

In a different simulation domain - finite element simulation - Thomke (1998)

explores learning during the research and development (R&D) of vehicle crash wor-

thiness at BMW. To illustrate learning over the course of the R&D project, Thomke

employs content analysis and extensive interviewing to construct time series illus-

trating engineers’ perceptions of the impact, both magnitude and direction, of differ-

ent variables on crashworthiness. The three examples included in the paper illustrate

the types of learning that could occur. For some variables, attitudes could remain

the same for the majority of the project and then experience a sudden jump in

importance. Others might fluctuate throughout the project.

Given the R&D setting and finite element approach in Thomke’s case study,

the model building approach may be similar to a DES study where the system

being modelled does not already exist. Building can largely be thought of as design:

engineers brainstorm a design for a vehicle based on their assumptions about how

the system will behave, outsource the construction of the model (called meshing)

and analyse results from the new model. Experimentation also clearly plays a role

in the learning process. Thomke points out that numerous learning points for the

engineers were based around the interaction of variables in the model that gave rise

to the crash dynamics observed.

In his closing comments Thomke reiterates the points outlined in the conceptual

discussion of the benefit of involving decision makers in model building.

‘Thus, I propose that the discipline required in developing computer

models will lead to advantages that go beyond making simulation models

available to users. It may also take a firm’s R&D knowledge from tacit to

explicit and, as a result, making it easily transferable within and between

firm boundaries’. (Thomke, 1998).

use. Thus it is difficult to pull out exactly what is learnt in building and what

is learnt in experimentation. For example, in Thomke’s study it might be that the

experimentation with variables in a crash model was the most beneficial for learning.

The one study found that directly compares model building and model use is

concerned with building qualitative models versus simulation use. Shields (2001)

performs an experimental study comparing the building of qualitative SD models

(i.e. casual loop diagrams) from a case study to the use of a SD simulation model

(generally referred to as a management flight simulator in the SD literature). Shields

manipulates these processes by either providing or not providing scripted facilitation.

Facilitators ask participants to describe their assumptions about interactions in the

model, predict what will happen when a chosen strategy is implemented and explain

results and outcomes following feedback on performance.

The study measured pre to post-test learning in five ways: an open ended ques-

tion asking participants to describe the system; two rating tasks where participants

rate the impact of variables on performance; and a diagramming task where par-

ticipants are provided with pre-labelled variables within the system. Marks were

given for the number of connections (complexity) and for inclusion of the direction

of feedback (SD).

Findings showed that the qualitative model building groups where a facilitator is

not provided demonstrated increased understanding of the complexity and system

dynamics of the problem. However, it was the facilitated simulation group that

demonstrated increased performance.