The Balancing Role of Best and Worst in Best-Worst Method

Best-Worst Method (BWM) is a pairwise comparison-based multicriteria decision-making method to elicit the relative importance of the criteria (and alternatives) from a decision-maker. While most elicitation methods are based on only one reference point, BWM is based on two reference points (the most important: best; and the least important: worst) which are chosen by the decision-maker and used to conduct the pairwise comparisons. This mechanism is a salient feature of BWM that is rooted from behavioral decision-making theories and leads to more reliable results. In this study, experimental analysis is used to show how the use of these two reference points could mitigate possible anchoring bias which is inherent in judgments provided by decision-makers. First, three hypotheses are formulated to compare the weights coming from BWM with the weights calculated based on only one reference point. Two experimental analyses are used to test the hypotheses. The results clearly show that using one reference point leads to anchoring bias. The biases created by the two reference points are in opposite direction. This implies that using the two reference points in BWM optimization model could cancel out the impact of anchoring bias.

Automated summary

The Best-Worst Method (BWM) is a multi-criteria decision-making method that uses pairwise comparisons to determine the relative importance of criteria. Unlike other methods, BWM uses two reference points to eliminate anchoring bias, resulting in more reliable results.