Comparison of d values for the 2-AFC (paired comparison) and 3-AFC discrimination methods: Thurstonian models, sequential sensitivity analysis and power

Using a model system comprising of low concentration NaCl vs water and a beverage system of varying strength apple juice, it was found that the 2-AFC (paired comparison) discrimination method yielded a higher dʹ than the 3-AFC method. Although the 3-AFC method is theoretically more powerful than the 2-AFC, the higher dʹ of the latter compensates for this, making it the more powerful of the two.