Intellectual Development Beyond Elementary School VI: Correlational reasoning

The establishment of relationships among variables is basic to prediction and scientific explanation. Correlational reasoning - the reasoning processes one uses in determining the strength of mutual or reciprocal relationship between variables - is, therefore, a fundamental aspect of scientific reasoning. Suppose, for instance, that a scientist is interested in finding out whether a correlation exists between the body weight of rats and the presence of a substance X in their blood. The establishment of a correlation requires an initial recognition of the four possible associations: (a) = heavy weight and presence of substance X; (b) = heavy weight and absence of substance X; (c) = light weight and presence of substance X; and (d) = light weight and absence of substance X. When variables can be dichotomized such as this, one may construct a 2x2 association table of the sort used to compute simple contingencies. In view of the fundamental role played by correlational reasoning in the investigative process, we asked ourselves the following question: How do high school science and mathematics students approach tasks that require correlational reasoning for successful solution? An answer to this question will indicate how students apply this important aspect of scientific reasoning and might suggest how this reasoning pattern could be enhanced through instruction.