Advanced Building Simulation

44 de Wit
Cooke and Goossens (2000) present a procedure for structured elicitation and
processing of expert judgment, which takes proper account of these principles. This
procedure was closely followed here. An outline is presented in the following section.
2.4.2.3 Set-up of the experiment
SELECTION OF THE EXPERTS
A pool of candidates for the expert panel was established by screening the literature
on relevant issues like wind-induced pressures on low-rise buildings in complex environments
and wind-induced ventilation of buildings. From this pool, six experts were
selected on the basis of the following criteria:
● access to relevant knowledge;
● recognition in the field;
● impartiality with respect to the outcome of the experiment;
● familiarity with the concepts of uncertainty;
● diversity of background among multiple experts;
● willingness to participate.
QUESTIONNAIRE
The experts were asked to assess the wind pressure difference coefficients for the case
at hand. As the wind pressure difference coefficient depends on the wind angle relative
to the orientation of the building, they were asked to give their assessments for
12 different wind angles, with intervals of 30� (cf. Figure 2.2). The case was presented
to the experts as if it were a hypothetical wind tunnel experiment, as this is a type of
experiment the experts were all familiar with.
Each expert’s assessment of a coefficient did not consist in a “best estimate”, but
in a median value plus a central 90% confidence interval expressing his uncertainty.
Table 2.3 shows the first part of the table the experts were asked to fill out for each
wind angle.
TRAINING OF THE EXPERTS
It would have been unwise to confront the experts with the questionnaire without giving
them some training beforehand. None of the experts but one had ever participated in
Table 2.3 Quantile values of the wind pressure difference
coefficients to be assessed by the experts for
each of the 12 wind angles
Wind angle Quantile values
5% 50% 95%
0�
30�
…