Magnitude Estimation of Visual Velocity,

摘要

The study was designed to measure how accurately subjects can estimate real movement in degrees per second and to determine whether the precision of the estimate can be improved with practice. The display apparatus was composed of an opaque strip of film with small perforations and was lighted from behind. Two subjects were tested twenty-one times over a broad range of velocities,and two others received an abbreviated schedule of testing. No systematic practice effects were noted across the twenty-one sessions,but some improvement was observed within the first session. No consistent bias of over-or-under-estimation was observed;the relationship between real and apparent movement was linear. The subjects made discriminations among 48velocity levels,spaced 0.2deg/sec apart;standard errors were approximately 1.0deg/sec. (Author)