Ruth Phelps, Ph.D.

TITLE: Branch Chief

COMPANY: Army Research Institute

Advisor: Dr. James Shanteau
Dissertation Title

Livestock Judges: How much information can an expert use?

Dissertation Abstract

Two experimental procedures were used to determine the number of dimensions used by livestock experts in making decisions: 1. Judgments were made of hypothetical gilts (female breeding pigs) described by verbal statements along 11 dimensions. 2. Judgments were made based on photographs of Poland-China breeding gilts. Judges used 9-11 pieces of information in the first procedures but were generally found to use fewer than 3 in the second. These outcomes were interpreted to mean that expert judges can integrate a large number of dimensions but that intercorrelations present in real stimuli tend to reduce the number of dimensions found. This finding suggests that experts may be able to use substantially more information than was previously imagined.


Ph.D., Psychology, Kansas State University, 1977