Date of Award


Document Type


Degree Name

Doctor of Philosophy (PhD)


Educational Theory, Policy, and Practice

First Advisor

James Wandersee


The main research focus of this study was on the regional differences in understanding of two groups of high school science students for a complex environmental scientific phenomenon known as the Dead Zone of the Gulf of Mexico. Participating high school students were drawn from Dead Zone source and effect areas---Iowa chemistry students and Louisiana environmental science students. Students were given a pre- and postinstructional survey concerning environmental issues---including the issue of the Dead Zone or hypoxia of the Gulf of Mexico. The treatment group visited a web site on the Dead Zone constructed for this study, and interacted with it for approximately 80 minutes. The control group did not view the material on the web site. Nine members of the treatment group in each location were videotaped while using the web site, and interviewed after its use. The "think-aloud" data generated during the web site use, and the clinical interview data, were analyzed using Chi's verbal analysis. Quantitative analysis of the pre- and postinstructional survey data, using NUD.IST(TM) software, indicated that there was little change in opinion as a result of using the web site. Qualitative analysis exposed areas of weak conceptual development prerequisite to understanding Dead Zone formation. Key deficiency areas are clustered around the concepts of water cycle, liquid density and connections between basins of the watershed. Some findings to be highlighted as a result of this study are: (1) Statistical analysis of the opinion survey did not indicate that 80-minute usage of the study's web site accounted for significant changes in the treatment groups' post-instructional survey scores. (2) Iowa students indicated they knew more about CAUSES as evidenced by higher scores on watershed-focused nodes in the web site use data, interview data, and in student drawings of the Dead Zone. (3) Louisiana students indicated they knew more about EFFECTS of the Dead Zone, as evidenced by higher scores on Dead Zone-focused nodesin the web site use data. They had approximately the same number of nodes as the Iowa students' interview data, but included more Dead Zone information in drawings of the Dead Zone.