Effects of progressively increasing the difficulty of training on sensitivity and strategic factors in olive oil tasting

Training schedules including progressive increments of difficulty lead to a better performance on a harder version of a discrimination task than non-progressive schedules that only include the hardest level of difficulty. A detection task in which participants had to detect whether the samples that they tasted contained a small amount of olive oil was used to test the relevance of this phenomenon in an olive oil tasting context. Two groups of participants received three training sessions with this task before receiving a final test of performance. In group hard-to-hard, olive oil concentration was kept low and constant throughout sessions and testing. In group easy-to-hard, olive oil concentration was high in the first training session. Olive oil concentration was progressively decreased across sessions, reaching the same level of the hard-to-hard group at the time of testing. Results showed better ability for detecting olive oil when participants were trained with progressively lower concentrations of olive oil than when the training program involved only the lowest (most difficult) one. Progressive training led participants to show a conservative bias that did not appear when training was only conducted with the most difficult discrimination.

► Easy-to-hard (ETH) effect was assessed in an olive oil evaluation context. ► Signal Detection Theory was used to assess sensitivity and strategic components. ► Better sensitivity and a conservative response bias were found after ETH training.