A simple cognitive method to improve the prediction of matters of taste by exploiting the within-person wisdom-of-crowd effect.

In our daily lives, we must often predict the level of others' satisfaction with something they have not experienced thus far. How can such a prediction be accurate? Existing studies indicate that, by referring to the extent to which people themselves have enjoyed something, they are able to predict others' future satisfaction, to some extent. In this study, we propose a method that can further improve such predictions. This method is expected to allow individuals to exploit the 'wisdom of the crowd' within a person, in terms of taste. Specifically, for a single target, participants in our study group produced two opinions from different perspectives: the degree to which they preferred something, and they estimated 'public opinion'. Utilising two behavioural studies and computer simulations, we confirmed the effectiveness of our method; specifically, blending the two opinions could enhance an individual's prediction ability. Subsequently, we mathematically analysed how effective our method is and identified several factors that influenced its efficiency. Our findings offer several contributions to 'wisdom-of-crowd' research.