Chapter 1 Quantitative research in education: Impact on evidence-based instruction

Quantitative research is based on epistemic beliefs that can be traced back to David Hume. Hume and others who followed in his wake suggested that we can never directly observe cause and effect. Rather we perceive what is called “constant conjunction” or the regularities of relationships among events. Through observing these regularities, we can develop generalizable laws that, once established, describe predictable patterns that can be replicated with reliability. This form of reasoning involves studying groups of individuals and is often called nomothetic and is contrasted with idiographic research that focuses on the uniqueness of the individual. It is clear that large-scale experiments with random assignment to treatment are based on nomothetic models, as are quasi-experimental studies where intact groups of people (e.g., students in a particular classroom) are assigned to treatments.