Paul M. Fitts

Bio: Paul M. Fitts is an academic researcher from Ohio State University. The author has contributed to research in topics: Task (project management) & Stimulus (psychology). The author has an hindex of 20, co-authored 27 publications receiving 10207 citations.

The information capacity of the human motor system in controlling the amplitude of movement.

Abstract: Information theory has recently been employed to specify more precisely than has hitherto been possible man's capacity in certain sensory, perceptual, and perceptual-motor functions (5, 10, 13, 15, 17, 18). The experiments reported in the present paper extend the theory to the human motor system. The applicability of only the basic concepts, amount of information, noise, channel capacity, and rate of information transmission, will be examined at this time. General familiarity with these concepts as formulated by recent writers (4, 11,20, 22) is assumed. Strictly speaking, we cannot study man's motor system at the behavioral level in isolation from its associated sensory mechanisms. We can only analyze the behavior of the entire receptor-neural-effector system. However, by asking 51 to make rapid and uniform responses that have been highly overlearned, and by holding all relevant stimulus conditions constant with the exception of those resulting from 5"s own movements, we can create an experimental situation in which it is reasonable to assume that performance is limited primarily by the capacity of the motor system. The motor system in the present case is defined as including the visual and proprioceptive feedback loops that permit S to monitor his own activity. The information capacity of the motor system is specified by its ability to produce consistently one class of movement from among several alternative movement classes. The greater the number of alternative classes, the greater is the information capacity of a particular type of response. Since measurable aspects of motor responses, such as their force, direction, and amplitude, are continuous variables, their information capacity is limited only by the amount of statistical variability, or noise, that is characteristic of repeated efforts to produce the same response. The information capacity of the motor Editor's Note. This article is a reprint of an original work published in 1954 in the Journal of Experimental Psychology, 47, 381391.

S-R compatibility : spatial characteristics of stimulus and response codes

Abstract: The present paper reports the results of two experiments designed to demonstrate the utility of the concept of stimulus-response compatibility in the development of a theory of perceptual-motor behavior. A task involves compatible S-R relations to the extent that the ensemble of stimulus and response combinations comprising the task results in a high rate of information transfer. Admittedly, degree of compatibility can be defined in terms of operations other than those used to secure a measure of information, for example, it could be specified in terms of measures of speed or accuracy. However, the present writers prefer the preceding definition because of the theoretican interpretation that they wish to give to compatibility effects. This interpretation makes use of the idea of a hypothetical process of information transformation or recoding in the course of a perceptual-motor activity, and assumes that the degree of compatibility is at a maximum when recoding processes are at a minimum. The concept of compatibility can be

S-R compatibility: correspondence among paired elements within stimulus and response codes.

Abstract: The present paper is the second dealing with the usefulness of the concept of S-R compatibility for behavior theory. This concept concerns the effects of a class of variables that influence task difficulty in experiments in which learning, complexity (amount of information), and discriminability are controlled. Compatibility effects are conceived as resulting from hypothetical information transformation processes (encoding and/or decoding) that intervene between receptor and effector activity. The rate of processing information is assumed to be maximum when these receding processes are at a minimum. The objective of the study of compatibility effects is to discover conditions under which these effects occur, and to establish principles that will permit specification of the nature and difficulty of perceptual-motor tasks in terms of (hypothetical) intervening information transformation processes. Such processes must be inferred, just as do constructs such as habit strength, from measures of performance obtained in appropriate experiments. The type of experiment of greatest interest for the present purpose is one in which it is possible to measure the rate of information trans-

Software Engineering: A Practitioner's Approach

Abstract: From the Publisher: Well-suited for both the student and the working professional,Software Engineering A Practitioner's Approach recognizes the dramatic growth in the field of software engineering and emphasizes new and important methods and tools used in the industry.

Perception and communication

Abstract: First published in 1958, this book has become recognized as a classic in its field. It marked a transition between behaviourist learning theory and the modern 'information processing' or 'cognitive' approach to perception and communication skills. It continues to provide a principal starting point for theoretical and experimental work on selective attention. As Professor Posner writes in his Foreword to the reissue: 'it remains of great interest to view the work in its original form and to ponder those creative moments when the mind first grasps a new insight and then struggles to work out its consequences.

Heuristics and Biases: The Psychology of Intuitive Judgment

Abstract: A review is presented of the book “Heuristics and Biases: The Psychology of Intuitive Judgment,” edited by Thomas Gilovich, Dale Griffin, and Daniel Kahneman.

Extensional versus intuitive reasoning: The conjunction fallacy in probability judgment.

Abstract: Perhaps the simplest and the most basic qualitative law of probability is the conjunction rule: The probability of a conjunction, P (A&B) cannot exceed the probabilities of its constituents, P (A) and P (B), because the extension (or the possibility set) of the conjunction is included in the extension of its constituents. Judgments under uncertainty, however, are often mediated by intuitive heuristics that are not bound by the conjunction rule. A conjunction can be more representative than one of its constituents, and instances of a specific category can be easier to imagine or to retrieve than instances of a more inclusive category. The representativeness and availability heuristics therefore can make a conjunction appear more probable than one of its constituents. This phenomenon is demonstrated in a variety of contexts including estimation of word frequency, personality judgment, medical prognosis, decision under risk, suspicion of criminal acts, and political forecasting. Systematic violations of the conjunction rule are observed in judgments of lay people and of experts in both between-subjects and within-subjects comparisons. Alternative interpretations of the conjunction fallacy are discussed and attempts to combat it are explored.