The Logic of Plausible Reasoning: A Core Theory

The paper presents a core theory of human plausible reasoning based on analysis of people's answers to everyday questions about the world. The theory consists of three parts:

• 1 a formal representation of plausible inference patterns; such as deductions, inductions, and analogies, that are frequently employed in answering everyday questions;
• 2 a set of parameters, such as conditional likelihood, typicality, and similarity, that affect the certainty of people's answers to such questions; and
• 3 a system relating the different plausible inference patterns and the different certainty parameters.

This is one of the first attempts to construct a formal theory that addresses both the semantic and parametric aspects of the kind of everyday reasoning that pervades. all of human discourse.     

The accuracy of self-administration and scoring on Holland's Self-Directed Search

This study assesed the extent to which Ss commit various types of errors when completing Holland's Self-Directed Search (SDS) entirely on their own. Nearly all Ss made some type of error and approximately half of the Ss made errors which affected their final three-letter summary codes. Almost one-fifth of the Ss made errors resulting in an incorrect high-point code. Whether or not Ss made errors that affected their summary codes was unrelated to the extent to which they were interested in knowing more about occupations or academic majors they might like. Neither were such errors related to whether Ss felt the occupations suggested by their summary codes seemed reasonable. Only slightly over one-third the Ss actually did feel that the occupations seemed reasonable.     

Seeing with the skin

A system for converting an optical image into a tactile display has been evaluated to see what promise it has as a visual substitution system. After surprisingly little training, Ss are able to recognize common objects and to describe their arrangement in three-dimensional space. When given control of the sensing and imaging device, a television camera, Ss quickly achieve external subjective localization of the percepts. Limitations of the system thus far appear to be more a function of display resolution than limitations of the skin as a receptor surface. The acquisition of skill with the device has been remarkably similar for blind and sighted Ss.     

CER suppression, passive-avoidance learning, and stress-induced suppression of drinking in the Syracuse high- and low-avoidance strains of rats (Rattus norvegicus)

The Syracuse strains of Long-Evans rats were selectively bred for good (SHA) or poor (SLA) avoidance learning in a two-way shuttle box, which resulted in a phenotypic difference that is correlated with behavior patterns indicative of emotional reactivity, SLA animals showing evidence of greater emotional reactivity than SHA animals. The first three experiments examined conditioned suppression of bar pressing and compared paired and unpaired conditioned- and unconditioned-stimulus presentations to evaluate the influence of conditioning versus primary aversive stimulation on baseline responding. SLA animals acquired conditioned suppression faster than SHA animals and also showed greater suppression of baseline responding than SHA animals. In Experiment 4, SLA animals learned a passive-avoidance task faster than SHA animals. In Experiment 5, SLA animals showed greater stress-induced suppression of drinking a weak quinine solution than SHA animals. These data are consistent with the hypothesis that SLA animals are more emotionally reactive than SHA animals.