Agreement between observers when the categories are not specified in advance

To test the agreement between two observers who categorize a number of objects when the categories have not been specified in advance, Brennan & Light (1974) developed a statistic A′ and suggested a normal approximation for its distribution. In this paper it is shown that this approximation is inadequate particularly when one, or both, of the observers place a fairly equal number of objects in all of their categories. A chi-squared approximation to the distribution of A′ is developed and is shown to work well in a variety of situations. The relative powers of A′ and the ordinary X² test for association are dependent on the type of ‘agreement between the observers’ that is assumed. However a simulation for a fairly general type of agreement indicates that the X² test is more powerful. As the X² test is also much easier to apply, it would seem preferable in most situations.     

The co-therapy relationship: Mutuality,agreement and client outcome

This project, utilizing a pretest and posttest design, studied interactions between co-therapists and the relationships of their interactions to client outcome. Six co-therapist pairs at a counseling center saw two clients in multiple treatments yielding twelve cases. The study investigated co-therapist relationships in regard to: (a) their level of mutuality or caring for their partners, (b) their ratings of the quality of their relationships, and (c) their agreement as to perceptions and behavior during sessions. Also investigated were: the relation of co-therapist interaction to client outcome and the personal growth of the therapists over the course of therapy. Results supported success claims of the literature concerning co-therapy.     

Logic of paradox revisited

Conclusion If, to return to the image with which I started this paper we consider the path of papers written on the logical paradoxes, then there is much to be learnt from the more recent additions, those by Chihara, Dowden and Woodruff included. However, the case for the paraconsistent approach to the paradoxes has not been weakened. In fact, it seems to me to have been strengthened. If we consider the path of papers, not as a signle line, but branching according to the approach to the paradoxes advocated, then the Logic of Paradox would, I still submit, be on the right track.     

Food anticipation and lever-directed activities in rats

Three experiments are described which elaborate some of the conditions under which rats will contact and manipulate a periodically presented retractable lever. Experiment 1 demonstrated that (i) initial manipulative oral and manual contact with the lever was facilitated if the rat had previous experience of food delivery in the experimental chamber; (ii) persistence in contacting the lever on successive presentations was a function of whether food continued to be presented in the experimental environment; and (iii) food satiation significantly reduced the tendency of the rat to contact the lever even though an expectancy of food had previously been established under conditions of food deprivation. Experiment 2 suggested that the tendency to approach and contact the lever was in part a function of the local moment-to-moment conditional probability of food delivery. Experiment 3 found that the probability of contacting the lever was higher during presentation of an auditory CS signaling a high rate of food delivery than during stimuli signaling no food at all. These results are interpreted as suggesting that the food-signaling aspects of an appetitive CS and that CS's ability to generate signal-directed behaviors are experimentall separable properties.     

Variation of the magnitude of the horizontal-vertical illusion with retinal eccentricity

The horizontal-vertical illusion was studied as a function of retinal eccentricity. It was found that the relation of illusion magnitude to vertical eccentricity is described by a U-shaped function with large amounts of reversed illusion for the more eccentric positions. Substantial effects due to horizontal eccentricity were also obtained, but these were not consistent across subjects. It is suggested that the flattening of the peripheral zones of the refracting surfaces of the eye may be involved in the variation of the illusion with retinal position, and that the astigmatic properties of the central portions of these surfaces may be a prime factor in the usual horizontal-vertical illusion.