Robinson G H
Department of Psychology, University of North Alabama, Florence 35632.
Percept Psychophys. 1992 Apr;51(4):363-78. doi: 10.3758/bf03211630.
In the present study, numerosity estimation was investigated. A two-parameter Stevens power law analysis was performed on a total of 944 subjects in six experiments. Two pulse ranges (2-17 or 17-253 pulses) and six pulse rates (either constant or randomly varied within trial blocks) were used, variously, in an unsuccessful attempt to find evidence for a psychological moment, under the supposition that the exponent (or, possibly, the measure constant) would become smaller as increasing numbers of pulses fell within the interval determined by each psychological moment. A single-parameter reanalysis of these six experiments under the initial value condition that a (standard) stimulus of one pulse be assigned a theoretical response (modulus) of one yielded single-parameter equations whose exponents were reliably less varied than those for conventional two-parameter equations in Experiments 1-4 (with randomly varying pulse rates from trial to trial) but not less varied in Experiments 5 and 6 (in which pulse rates were constant within trial blocks). It was concluded that the variable pulse rate condition, with its reduced exponent variability and presumed reduced temporal confounding, provides a more valid estimate of the single-parameter power law exponent for numerosity, which was found to be 0.80.
在本研究中，对数字估计进行了调查。在六个实验中，对总共944名受试者进行了双参数史蒂文斯幂律分析。使用了两个脉冲范围（2 - 17或17 - 253个脉冲）和六种脉冲率（在试验块内要么恒定要么随机变化），以不同方式试图寻找心理时刻的证据，假设随着越来越多的脉冲落在由每个心理时刻确定的区间内，指数（或者可能是测量常数）会变小。在初始值条件下对这六个实验进行单参数重新分析，即给一个脉冲的（标准）刺激分配理论响应（模量）为一，得到的单参数方程的指数在实验1 - 4（试验间脉冲率随机变化）中比传统双参数方程的指数变化可靠地更小，但在实验5和6（试验块内脉冲率恒定）中变化并不更小。得出的结论是，可变脉冲率条件下指数变异性降低且假定时间混淆减少，为数字的单参数幂律指数提供了更有效的估计，该指数为0.80。
