Accession Number : AD0657303

Title :   SCALING EXTRAVEHICULAR AND EN ROUTE JUDGMENTS OF AUTOMOBILE SPEED.

Descriptive Note : Technical rept.,

Corporate Author : WASHINGTON UNIV SEATTLE PSYCHOPHYSICS LAB

Personal Author(s) : Semb,George

Report Date : 1967

Pagination or Media Count : 37

Abstract : Automobiles were used to investigate psychophysical laws which govern judgments of three forms of subjective speed: linear speed; approach speed; and en route speed. By the method of magnitude estimation, subjective values of all three were found to be power functions of their corresponding physical velocities with exponents of 1.00, 1.75, and 1.94. The relation between category and magnitude scales of en route speed was also studied. Characteristic of prothetic continua, the category scales are concave downward when plotted as a function of the magnitude scales. In order to determine the descriptive value of Weber's Law for en route velocity, several difference thresholds were taken at velocities from 20 to 60 miles per hour. The results show that Weber's fraction, delta I/I, is constant over this range. (Author)

Descriptors :   (*VISUAL PERCEPTION, *PSYCHOLOGICAL TESTS), (*VEHICLES, *VELOCITY), PSYCHOPHYSICS, ERRORS, ROADS, MOTION, ACCELERATION, DECELERATION, MEASUREMENT, LEAST SQUARES METHOD, STATISTICAL ANALYSIS

Subject Categories : Psychology

Distribution Statement : APPROVED FOR PUBLIC RELEASE