DANBURY -- Christopher Longo, chairman of the Bethel High School science department, will defend his dissertation Saturday for a doctoral degree in Instructional Leadership at Western Connecticut State University. The dissertation is titled "Effects of an inquiry-based science program on critical thinking, science process skills, creativity and science fair achievement of middle school students." Longo's study took place at Bethel Middle School from October 2010 to April 2011. The presentation will begin at 10 a.m. and last 30 minutes. It will be held in the south ballroom of the Westside Student Center. The district has others in the doctoral program who will complete their work in the next few years. They are Bethel High teachers Jessica Galbraith, Reine Issa, Mary Fernand and Karen Fildes, and Bethel Middle School teacher Rod Doble.