Letter Span Research Articles

Temporal Structure of Letter Groups and Span of Perception

The span of perception for letter groups depends on number of letters presented, length of presentation and structure of the groups. The experiment reported varied the temporal structure of the groups, leaving the total number of letters constant. Groups of 12 letters were presented as a whole or in two or more successive “units.” The total time of presentation was 1–5 sec. In the first experiment each unit was visible until the next appeared, in the second experiment units were visible only during 1/4 sec., although intervals between successive units were kept constant. The following conclusions emerged: (a) The visual presence of units did not affect the reproduction for durations over 0.25 sec., except in the 12-letter presentations. (b) 2×6 letters gave better results than either simultaneous presentation or other divisions; temporal separation was 0.75 sec. (c) Higher order approximations to Dutch have more influence on 3 × 4, 2 × 6 and 1 × 12 letters than on 4 × 3 and 6 × 2 letters. (d) A serial order effect exists: central units are reproduced less well than first and last units. It is suggested that handling a fixed amount of information within a fixed period is limited on the one hand by confusion between simultaneous elements and on the other hand by the interaction between successive units presented too rapidly to allow for proper operation of immediate memory. The difference between span of perception and span of memory is stressed.

A Comparison of Immediate Memory Span for Digits, Letters, and Words

(1957). A Comparison of Immediate Memory Span for Digits, Letters, and Words. The Journal of Psychology: Vol. 44, No. 2, pp. 319-327.

On the Redintegrative Perception of Words

According to Solomon and Postman, When a stimulus-pattern is presented at short durations or at low illumination-intensities, only fragments of the total wordstimulus are 'effective.' Such a stimulus-fragment may be considered to represent a point on the generalization-dimension of stimulus-patterns capable of eliciting the correct verbal response.' Certain questions regarding this statement immediately present themselves: (1) Where in the word are the stimulus-fragments that are the effective cues? (2) What conditions attend the redintegrative leap from the fragment to the correct whole-response? A partial answer to the first question is given by Erdmann and Dodge, Wagner, and others who found in nonsense arrangements of letters that the first and last letters were often correctly recognized while the middle letters were not.2 This finding needs to be checked for meaningful words. Also only with meaningful words can the second question be answered. Words of length greater than the individual's span of apprehension for letters were chosen as the exposure-material and were so chosen that the responses ranged from correct to fragmentary reports. Ever since Cattell's experiments, the crux of the problem seems to be why familiarity and meaning make it possible for a S to surpass his span for unconnected letters.8 One may experimentally induce such superiority by 'building in' familiarity, as in Solomon and Postman's experiment, or by using extraneous organization, as in Vanderplas' study.4 A direct, immediately available measure of familiarity can, however, be found in the individual's ability to define a word. Are words, as equated in Thorndike's frequency of usage, perceived more readily in short exposures when S can define them than when he can not? Does the ability to define have any relation to the ability to recognize the stimulus-word among alternatives presented after an unsuccessful recognition? The study of the function of various aids to recognition may provide a solution to Cattell's problem.

Effects of Practice on the Perceptual Span for Letters

Effects of Practice on the Perceptual Span for Letters

The Interrelationship of Conditions of Difficulty: I. The effect of Change in Number at Various Spatial Separations on Simultaneous Letter Span

The Interrelationship of Conditions of Difficulty: I. The effect of Change in Number at Various Spatial Separations on Simultaneous Letter Span

The Interrelation of Conditions of Difficulty: II. Number, Spatial Separation, and Illumination as Conditions of Simultaneous Letter Span

The Interrelation of Conditions of Difficulty: II. Number, Spatial Separation, and Illumination as Conditions of Simultaneous Letter Span