| This study explored how undergraduate students in a new problem-centered General Chemistry Laboratory curriculum achieved cognitive growth. The new curriculum had three instructional segments: the highly-structured, semi-structured, and open-ended segments. The pedagogical approaches adopted were expository, guided-inquiry, and open-inquiry styles, respectively. Sixty-seven first-year undergraduate students who enrolled in the course in Spring semester, 2000, at Columbia University and three Ph.D.-level chemistry experts were included in the study. A qualitative approach was used including data collection through “think-aloud” problem solving; however, quantitative data such as test scores were also used. The findings from this study confirmed that chemistry experts possessed sophisticated and domain-specific conceptual knowledge structures; they mobilized and applied conceptual knowledge in conjunction with use of heuristics, tacit knowledge, and experience in authentic problem solving. They validated the new curriculum design in preparing students for inquiry-type of problem solving. For novices, solving of semi-structured before ill-structured problems had a positive effect on the solvers' chance of success in solving the latter type of problems as their abilities to mobilize and apply conceptual knowledge and use effective strategies appeared to be critical for successful problem solving. Students in the new course curriculum had grown cognitively as evidenced by their performance on the Case Study projects and Final Examination. High academic achievers were found to perform well independently while the medium and relatively low academic achievers should benefit from sustained and intensive instruction. It is proposed that ill-structured problems should be used to assess and identify the best from the better students. Finally, it was found that no significant change in students' attitudes had resulted from their curriculum experience. Gender and cognitive style preferences may explain the preliminary signs of a bilateral change. Since students in chemistry courses are coming from increasingly diverse backgrounds, courses adopting a pedagogical approach that includes, (1) sequencing from the more expository to guided- and open-inquiry learning experiences for students, and (2) emphasizing a balance between content, context, concepts, and science processes, seem to be of the type that is more conducive to produce students of the qualities which chemistry educators have described as “ideal.”... |
