摘要:

The major types of models that have been proposed to account for the psychophysical data that are obtained when the stimulus differences are small are described briefly. Because it is clear that contingency variables, such as presentation schedules and payoffs, as well as the physical stimuli affect the response probabilities, recent models have included a trial dependent decision mechanism in addition to the (usually) static sensory one. Such models all appear to be special cases of two very general, but mathematically distinct, families of models, which are formulated in eqns. 1 and 5. Hypotheses about how the subject selects the response‐bias parameters of the decision process are examined. The assumption that they are chosen so as to maximize the expected payoff leads to incorrect predictions for special cases of both families. The alternative hypothesis studied is that the bias parameters are altered from trial to trial on the basis of information feedback according to one or another stochastic learning model. Primary attention is paid to the asymptotic expected values predicted for these parameters. Several such learning processes are described, their relations to static psychophysical models outlined, and their ability to explain data discusse

ISSN:0950-561X    

DOI:10.1111/j.2044-8317.1964.tb00240.x

出版商:Blackwell Publishing Ltd    

年代:1964

数据来源: WILEY

摘要:

If an accessory stimulus regularly precedes a critical stimulus at a fixed inter‐stimulus interval then the shorter the interval the lower the threshold for the critical stimulus. Three hypotheses which might explain this are discussed, and two experiments described. Experiment 1 shows that varying the intensity of an accessory stimulus does not affect the extent of the threshold fall it produces. Experiment 2 confirmed a prediction that randomizing inter‐stimulus intervals over a small range would allow the threshold to fall as the mean inter‐stimulus interval decreased at long mean intervals but not at short ones. Taken with earlier results, these experiments indicate that the subject lowers his threshold during a range of time about the end of the inter‐stimulus interval in which he expects that the stimulus may occur. It is also shown that the extent of the fall in threshold is inversely proportional to the length of this range of expectation, and that the latter appears to be directly proportional to the duration of the inter‐stimulus interval.This variation in threshold level is considered in terms of the model of the threshold provided by signal detectability theory. It is shown that the threshold falls are due to changes in the criterion computed by the subject, rather than in the sensory noise. This model is also successfully used to predict the extent of the shifts in detection rate that occur as the inter‐stimulus interval alters, on the assumption that subjects attempt to keep their false positive rates constant. Finally it is suggested that in computing the appropriate criterion for each inter‐stimulus interval the subject uses a simple approximate method rather than the more complex

ISSN:0950-561X    

DOI:10.1111/j.2044-8317.1964.tb00241.x

出版商:Blackwell Publishing Ltd    

年代:1964

数据来源: WILEY

摘要:

Three studies are reported in which results obtained by analysis using the multi‐dimensional ‘unfolding’ method are compared with those obtained by multi‐dimensional scaling. Attitudes of undergraduates towards crime, political parties and types of accommodation were assessed by presenting the stimuli two at a time and asking subjects to indicate preference as well as rate the differences between each pair of stimuli. Subjects were also asked to indicate whether they liked, disliked or felt indifferent towards each of the stimuli. Samples of approximately 200, 500 and 1,000 subjects respectively were used in the three studies. Where the individual differences in attitudes were relatively small, as in the crimes data, the two methods gave equally adequate representations of the data. However in their attitudes towards political parties the students showed large individual differences and this was reflected in considerable disparity between the results obtained by the two methods. An attempt was made to combine the two methods to investigate distortion produced by strong negative attitudes and the results obtained were linked to a theory of psychological balance. This theoretical explanation seemed appropriate to the results obtained from the study of students reactions to different types of accomm

ISSN:0950-561X    

DOI:10.1111/j.2044-8317.1964.tb00242.x

出版商:Blackwell Publishing Ltd    

年代:1964

数据来源: WILEY

摘要:

This paper considers five basic questions of item analysis and describes an integrated approach for obtaining the answers which utilizes the methods of probit and fractile graphical analysis. Item difficulty is interpreted as the limen at which 50 per cent of the subjects pass; discriminating power is given by the probit regression coefficient; the item‐ability relation is specified by the probit regression equation; chi square provides an objective test of whether or not the item meets the normal ogive assumption; and plotting items in terms of the limen and regression coefficient permits the selection of items comparable in terms of ability, difficulty, and discrimination. Techniques for the practical application of this approach are also outlined and illustrate

ISSN:0950-561X    

DOI:10.1111/j.2044-8317.1964.tb00243.x

出版商:Blackwell Publishing Ltd    

年代:1964

数据来源: WILEY

摘要:

A new method for analytical rotation to oblique simple structure is described. Orthogonal simple structure is achieved by means of any of several existing rotation methods and this is then transformed into an oblique solution.

ISSN:0950-561X    

DOI:10.1111/j.2044-8317.1964.tb00244.x

出版商:Blackwell Publishing Ltd    

年代:1964

数据来源: WILEY

ISSN:0950-561X    

DOI:10.1111/j.2044-8317.1964.tb00245.x

出版商:Blackwell Publishing Ltd    

年代:1964

数据来源: WILEY

ISSN:0950-561X    

DOI:10.1111/j.2044-8317.1964.tb00246.x

出版商:Blackwell Publishing Ltd    

年代:1964

数据来源: WILEY

ISSN:0950-561X    

DOI:10.1111/j.2044-8317.1964.tb00247.x

出版商:Blackwell Publishing Ltd    

年代:1964

数据来源: WILEY

ISSN:0950-561X    

DOI:10.1111/j.2044-8317.1964.tb00248.x

出版商:Blackwell Publishing Ltd    

年代:1964

数据来源: WILEY

ISSN:0950-561X    

DOI:10.1111/j.2044-8317.1964.tb00249.x

出版商:Blackwell Publishing Ltd    

年代:1964

数据来源: WILEY