A Bayesian Network Approach for Modeling the Influence of Contextual Variables on Scientific Problem Solving

This paper describes the causal relationships between students’ problem-solving effectiveness (i.e. reaching a correct solution) and strategy (i.e. approach) and multiple contextual variables including experience, gender, classroom environment, and task difficulty. Performances of the IMMEX problem set Hazmat (n~33,000) were first modeled by Item Response Theory analysis to provide a measure of effectiveness and then by self-organizing artificial neural networks and hidden Markov modeling to provide measures of strategic efficiency. Correlation findings were then used to link the variables into a Bayesian network representation. Sensitivity analysis indicated that whether a problem was solved or not was most likely influenced by findings related to the problem under investigation and the classroom environment while strategic approaches were most influenced by the actions taken, the classroom environment and the number of problems previously performed. Subsequent testing with unknown performances indicated that the strategic approaches were most easily predicted (17% error rate), whereas whether the problem was solved was more difficult (32% error rate).