Reliability of multiple classifications

Cohen's kappa index is reformulated for multiple classifications based on exchangeable random variables. It is found that kappa is between 0 and 1 inclusive. Two characterizations for kappa are stated in terms of the relationship between such random variables. Within the normal test score model, kappa increases with test reliability and test length. Furthermore, when based on binary classifications, kappa is an inverse U-shaped function of the cutoff score. These trends also hold for the beta-binomial test score model.Paper read at the Spring meeting of the Psychometric Society, Bell Laboratories (Murray Hill, New Jersey), March 1976.The editorial assistance and helpful comments of Leonard S. Feldt, Sarah P. Seaman-Huynh, and the three referees are gratefully acknowledged.     

The effect of punishment and reinforcement procedures on a stutterer's factor II avoidance response

The purpose of this clinical experiment was to investigate the manipulability of a Factor II avoidance response (arm movement). The substantive hypothesis under test was that its suppression would be enhanced by repeated punishment sessions. During the first of nine therapy sessions response-contingent negative stimulation was not delivered. In the next five, after a base-rate period, “wrong” was made consequent upon the target response. In each of these sessions the suppression of arm movement was apparent. However, the magnitude of the suppression decreased from session to session. Evidently, the continued use of punishment did not enhance suppression. Because of this finding procedural changes were introduced in the next three therapy sessions. Verbal praise was added as a consequence of increasingly stringent omission criteria and three consecutive units of praise led to time-out from the reportedly fatiguing task of continuous speech. A marked reduction and then complete extinction resulted. Moreover, learning was evidenced since the frequency of arm movement lessened in the base-rate period of each session.     

Further analysis of stuttering as a phonetic transition defect

This article presents a further analysis of stuttering as a phonetic transition defect. Three types of phonetic transitions are identified. Two of these occur within words and represent sites where stutterings are readily detectable. The third transition involves movement from the end of one word to the beginning of the next. Spectrographic evidence is provided to show that stuttering also occurs at points of transition of this type. The same data are interpreted relative to their implications for stuttering theory, research, and therapy.     

The universal nature of human intelligence: Evidence from games

Mentally retarded individuals have relatively greater difficulty in dealing with strategic games and puzzles than with many other tasks. Consequently, it is of interest to find that strategic games have been played since ancient times, are played throughout the world, and that players who excel are frequently considered wise. Hidden within the more obvious differences between cultures, strategic games are an invariant expression of certain universal intellectual traits.     

Attention demands of movements as a function of their duration and velocity

The attention demands of initiating and controlling discrete movements were examined as a function of their movement time (MT) and average movement velocity. Experiment 1 showed that the attention required to execute a movement decreased as MT decreased, although Experiment 2 through independently manipulating MT and movement velocity, revealed that movement velocity is the key determiner of attention demands rather than MT. The attention demands of preparing a high velocity movement are greater than during its execution with the reverse being the case for relatively slow velocity movements. The results are compatible with the view that it is the initiation of error corrections that are attention demanding (Keele 1973).     

Habit reversal vs. negative practice treatment of nailbiting

A previous study of the habit reversal treatment of nailbiting was extended by using more subjects (97) and a comparison with an alternative method (negative practice). Negative practice reduced nailbiting episodes by about 60% whereas habit reversal reduced nailbiting episodes by about 99% throughout the 5-month follow-up.     

A controlled group study of pedestrian-skill training for the mentally retarded

Pedestrian-skills training procedures were compared using 30 mentally retarded institutionalized adults. Ten subjects were randomly assigned to a no-treatment control group and ten subjects were assigned to each of two modes of pedestrian-skills training. The training methods included a form of individualized classroom training consisting of the practice of correct behavior using movable figures on a scale model of an intersection, vs independence training which emphasized self-evaluation of performance, social reinforcement, sign recognition and the utilization of a mock-up of an intersection on the hospital grounds. Data were taken on sign recognition, verbal and performance based responses to classroom training of pedestrian skills, performance of skills at an intersection on the hospital grounds, and performance of pedestrian skills in the community. Independence training proved to be significantly more effective than no treatment or classroom training. In addition, classroom training proved to be significantly more effective than no treatment at all.     

Effects of erotic stimuli on sexually functional and dysfunctional women: Multiple measures before and after sex therapy

A group of 11 women entering sex therapy for treatment of low arousal, and a comparison group of 11 women experiencing no arousal deficit, viewed an erotic film, listened to an erotic audiotape, and engaged in sexual fantasy during two experimental sessions. Session I occurred pre-treatment for the low arousal group. Session II occurred post-treatment. The adequate arousal group was tested at comparable points in time. Sexual arousal was measured subjectively by self-rating and physiologically by a vaginal photoplethysmograph. Contrary to expectation, the two groups showed equivalent significant increases in physiological response during the erotic stimuli in both sessions. However, the adequate arousal group rated subjective arousal significantly higher than the low arousal group in Session I, while no difference was found between the groups in Session II. Significant correlations were present between physiological response and ratings of several affective reactions to the audiotape, though few significant correlations were found between physiological and subjective sexual arousal measures. These data indicate a discrepancy between genital responses and ratings of sexual arousal for which several interpretations are offered.