PEST REDUCES BIAS IN FORCED CHOICE PSYCHOPHYSICS

Authors
  1. Taylor, M.M.
  2. Forbes, S.M.
  3. Creelman, C.D.
Corporate Authors
Defence and Civil Inst of Environmental Medicine, Downsview ONT (CAN);Toronto Univ, Toronto ONT (CAN) Dept of Psychology
Abstract
Observers performed several different detection tasks using both the PEST adaptive psychophysical procedure and a fixed-level (method of constant stimuli) psychophysical procedure. In two experiments, PEST runs targeted at P(C) = 0.80 were immediately followed by fixed-level detection runs presented at the difficulty level resulting from the PEST run. The fixed-level runs yielded P(C) about 0.75. During the fixed-level runs, the probability of a correct response was greater when the preceding response was correct than when it was wrong. Observers, even highly trained ones, perform in a nonstationary manner. The sequential dependency data can be used to determine a lower bound for the observer's "true" capability when performing optimally; this lower bound is close to the PEST target, and well above the forced choice P(C). The observer's "true" capability is the measure used by most theories of detection performance. TRUNCATED
Report Number
83-P-36 — Research Paper
Date of publication
01 Jan 1983
Number of Pages
8
Reprinted from
J Acoust Soc Am, vol 74, no 5, 1983, p 1367-1374
DSTKIM No
84-02220
CANDIS No
121609
Format(s):
Originator's fiche received by DSIS;Hardcopy

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