Date of Award


Document Type


Degree Name

Master of Science


Department of Systems Engineering and Management

First Advisor

Kim Sydow Campbell, PhD


Environmental impact statements (EISs) are prepared so decision makers can consider the potential environmental impacts of a proposed action. The National Environmental Policy Act mandates that EISs be clear, concise, and to the point so decision makers and the lay public can understand them, however, several authors assert these documents do not meet this requirement. To examine the usability of EISs, a 1994 AFIT GEEM student, Jill A. Easterly, altered visual and linguistic discourse elements in portions of sample ElSs and then a pool of readers answered objective questions about passages from these EISs. Easterly measured the effect of presence or absence of cohesive discourse elements on readers' performance. Dependent variables were accuracy (number of correct responses) and efficiency (time to answer the questions). Her results showed no statistical significance between or among the different treatments. She also collected subjective data regarding readers' perceptions of the documents they reviewed. This thesis evaluated Easterly's subjective data to determine if there was a statistically significant difference in readers' perceptions of document usability with respect to consistency of discourse elements. The results of this thesis paralleled those found by Easterly: there was no statistical significance between or among the different treatments.

AFIT Designator


DTIC Accession Number