Research Article

An Effective Approach to Input Variable Selection for Preliminary Cost Estimation of Construction Projects

Table 3

Variable groups and coefficients.

Variable groupEigenvalueVariance (%)Input variablesVariable coefficients

Variable group (V1)Project size
Project type
Project complexity
Project scope
Project duration
Project location
Bridge type
Number of bridges

Variable group (V2)Existence of groundwater
Bridge type
Number of bridges
Soil type

Variable group (V3)Project location
Inflation rate
Site topography
Soil type

Input variables which are clustered more than one variable group.