Strategic cost advice and the effect of cognitive error

The formulation of early stage building project cost advice for clients requires the professionals concerned to exercise judgement. The exercise of judgement is a human cognitive process that can be subject to errors, bias and heuristics. One of the groups of error that affects judgement is "cognitive error". This group includes sample size error, base rate error and logic error. This study identifies that construction professionals make systematic errors of judgement due to cognitive error. The paper reports the development of an appropriate measuring instrument and the results of its application to a group of thirty-six practitioners. Subjects were tested on their propensity to make errors in judgement via text problems that were set in their own subject specific domain. The results of the work revealed that the subjects displayed the same level of error in response to the context-based word problems as had been displayed in previous studies on other biases. The paper goes on to report the findings of a follow up study to determine the significance of these errors in practice. The paper concludes by setting out the case for the development of training a package to help practitioners to deal with the propensity to make errors.