How much harder are indifference adjustments? An experiment on the cognitive effort in multi-criteria decisions

This study investigates the cognitive effort required for indifference adjustments (IAs) compared to preference statements (PSs) in multi-criteria decision analysis. While IAs provide substantially more preference information than PSs do, the empirical question of whether the additional cognitive burden is justified remains underexplored. We conducted a field experiment with 83 Austrian roofing professionals who made product decisions about roofing tiles. Participants evaluated products described by 2-4 attributes using both the PS and IA methods, with response time and subjective difficulty ratings as effort measures. Surprisingly, we found that IAs required only 10%–20% more cognitive effort than PSs despite their significantly higher information yield. The effort difference increased slightly with the number of attributes, but remained modest throughout. Our findings suggest that the majority of cognitive effort in both methods stems from comprehending the alternatives rather than making an actual preference judgment or indifference adjustment. These results have important implications for multi-criteria decision support system design, suggesting that IAs offer an attractive trade-off between information gain and cognitive burden.