The approach in which researchers use the existing data to create groups for…

Concept

In causal-comparative research, the researcher studies a possible cause-and-effect relationship after the relevant condition or event has already occurred. The groups already exist, so the researcher does not manipulate the presumed causal variable or randomly assign participants.

Application

Here, the comparison groups are formed from existing data rather than created through an intervention or random assignment. This is the defining procedure of ex post facto, or causal-comparative, research.

Contrast

• Operational research uses mathematical models, optimization, and quantitative analysis to support decisions in complex systems.

• Experimental research deliberately manipulates an independent variable and ordinarily uses control procedures to test its causal effect.

• Quasi-experimental research evaluates a researcher-introduced intervention but lacks full random assignment, often using intact groups.

Result

Therefore, the approach described is ex post facto research.