Removing certainty from the equation: Using choice architecture to increase awareness of risk in engineering design decision making

The mediated model of determinants for risky decision making theorizes that decision making is influenced by a decision makers risk propensity and risk perception. Risk propensity is an individual's tendency to take or avoid risks. Where as risk perception is the decision makers’ assessment of how risky a situation is in terms of probabilistic estimates. Risk perception is also influenced by risk representation, which is the way risk is presented to the decision-maker. Modifications were made to the choice architecture of a trade-off matrix to test whether representing risks as embedded characteristics of design options influences engineering choice. Senior civil engineering students (n=98) were asked to consider trade-off matrices for two design options using criteria provided in a decision scenario. Half of the participants randomly received the control version of the trade-off matrix where risk was shown as an additional sixth criteria. The other half of participants received the modified tradeoff matrix where risk shown as a confidence interval. Illustrating risk as a separate criteria appears to significantly (p=0.04) influence users decision making leading participants to discount risk. Nearly 70% chose the more risky option. Yet, when risk was shown as a confidence interval participants were evenly split between the high and low risky option. The risk representation seems to meditate or counter balance those with a high propensity for risk. When controlling for risk propensity the results are even more significant (p=0.02). Meaning, those with high risk propensity more frequently choose the risky choice given the control version (as expected) but that did not hold true for the modified version, when shown as a confidence interval. Understanding how decisions are influenced by risk representation can lead to designing choice architecture that helps engineers and contractors make decisions that are in their own, or their clients’ best interests.