恒常法における反応カテゴリー数の影響
Effect of the number of categories of constant stimuli
methods
基礎心理学研究、2017、36、85−91．
The Japanese Journal of Psychonomic Science, 2017, 36, 85-91.
Abstract
Simulation of experiments of constant stimuli methods demonstrated that the three or four categories (3AFC or 4AFC) methods are preferable to the two categories (2AFC) method
from the statistical perspective. Point estimates of the slope and position parameters, mu and sigma, of psychometric functions of cumulative normal distributions
were calculated using Bayesian analysis of the data generated by simulation experiments of constant stimuli methods. The root mean square errors (RMSEs) of estimates
of slope parameter sigma for the two categories method were approximately 1.4 times those for the three or four categories methods.
Just noticeable difference is given by a constant time of sigma. RMSEs of estimates of mu corresponding to the point of subjective equality were
approximately the same magnitude among the two and four categories methods, but RMSE of estimates of mu for the three category method was
about three fourths of those for the two or four categories methods.