Tests of symmetry in three-way contingency tables

Three-dimensional contingency tables are analyzed, with one variable (e.g., sex) as a factor, and with a natural relation between the other variables (e.g. left and right eye vision). Models of special interest, like symmetry and proportional symmetry between the related variables, and homogeneity across the factor levels, are investigated. Maximum likelihood estimators of parameters and partitions of chi-square goodness-of-fit statistics are explicitly presented; the independence of certain models is noted, and an example is discussed.     

The dimensionality of vocational commitment: An empirical assessment of Ramsay's three-factor model with trainee nurses

The validity of Ramsey's three factor model of vocational commitment – consisting of ego-involvement (ranging from altruism to self-orientation), pre-dispositions, and occupational possibilities – is examined Although no data is provided relevant to the altruism end of the ego-involvement continuum, analyses of data from a sample of trainee nurses indicated that the three measures of self-orientation, predispositions, and occupational possibilities possessed satisfactory internal consistency and discriminant validity, thus providing support for the three-dimensional model.     

Electromyographic indications of laryngeal-area activity during stuttering expectancy

Using surface electrodes, mean microvolt values of laryngeal-area muscle activity were determined for 13 male and 6 female stutterers during 10-sec periods in which single words were silently read and stuttering expectancy was indicated. No significant differences in levels of laryngeal-area muscle activity were found between periods of fluency expectancy and stuttering expectancy preceding both fluent and stuttered speech. The results were interpreted as being nonsupportive of the hypothesis that a breakdown in stutterers' laryngeal-area muscle activity occurs during moments of stuttering expectancy. In addition, the results suggest that the most common rationale for the utilization of laryngeal biofeedback procedures to enhance fluency should be questioned.     

Visual laterality patterns for pure- versus mixed-list presentation

In Experiment 1, an overall left visual field advantage for nonverbal form recognition was found in a pure list of forms, but an overall right visual field form recognition advantage was found when the form trials were randomly intermixed with word recognition trials. Form complexity also influenced the form recognition laterality pattern, but the complexity effects were independent of (i.e., additive with) those produced by randomly mixing forms with words. Experiment 2 found that the mixed-list laterality pattern was unchanged by a pretrial cue indicating whether a word or form would follow. Experiments 3 and 4 demonstrated that holding two nouns in memory on each trial in a pure list of forms has much the same effect on laterality pattern as mixing forms with words but that the combined effect of these two variables is no larger than the effect of either variable alone. The entire pattern of results suggests that (a) laterality patterns are caused by the interaction of several factors, (b) the effects of random mixing and concurrent verbal memory are both caused by selective left-hemisphere activation, and (c) the form-complexity effects are caused by some other mechanism--perhaps subtle difference in stimulus codability.     

Prediction as a means of inducing tolerance

Female subjects were exposed individually to the attitude item responses of a similar or dissimilar stranger. They were asked either to copy down the stranger's attitudes or to predict (with accurate feedback) how the stranger answered each item. Predict subjects were found to be more tolerant of the dissimilar stranger than were Copy subjects, while both groups were equally attracted to the similar stranger. It was suggested that training people to anticipate disagreements may be a useful way of fostering tolerance.     

Communicative stress and stuttering frequency during normal,whispered, and articulation-without-phonation speech modes

The effect of communicative stress on the frequency of stuttered syllables in 12 adult stutterers reading six different but equivalent passages using normal voicing, whispering, and articulation-without-phonation speech under a stress and a non-stress condition was studied. Although the frequency of stuttering was significantly greater in the normal voicing mode than in the whispering mode and greater in the whispering mode than in the articulation-without-phonation mode, no differences were found between the stress and the nonstress conditions with respect to stuttering.     

The neurotic paradox and self-punitive behavior in humans

Human subjects learned a key-pressing response in order to avoid or escape shock. The reinforcement contingencies were then changed to punishment or to regular nonpunished extinction. The locus of shock onset and offset was systematically varied during the punishment phase. More subjects reported awarencess of the change in the nonpunished extinction group. By inference, the punished groups responded more, and thus the results appear analogous to animal studies on vicious circle, self-punitive responding. Discriminability of change from acquisition to extinction appeared to affect detection of the change.     

Alcohol breath tests: Criterion times for avoiding contamination by “mouth alcohol”

Using either a gas chromatography or an infrared absorption technique, series of blood alcohol concentrations (BACs) determined by breath tests were obtained from human subjects immediately subsequent to their having only oral contact with beverages ranging in ethyl alcohol concentration from 4% to 95% +. Times for total dissipation of mouth alcohol residuals to a level of practical nonsignificance ranged from 10 to 19 min. Dissipation rates were an inverse and approximately exponential function of the ethyl alcohol concentration of the beverage and were greatly shortened by rinsing the mouth with warm (34°C) water prior to testing. The results are discussed in terms of their relevance to the methodology of a number of research studies employing BAC breath-testing equipment.