Which statement best characterizes pre-experimental research designs?

Which statement best characterizes pre-experimental research designs?

• A. They typically lack a Control Group
• B. They always include Random Assignment
• C. They use Double-Blind procedures
• D. They require large samples

Answer: (A)

Pre-experimental designs are simple, early-stage setups that lack rigorous control to establish causality. They usually involve a single group that receives the intervention and may have no comparison group or only a nonrandom, non-equivalent one. Without randomization and proper control, threats to internal validity loom, so these designs commonly do not include a true control group. That makes the statement about typically lacking a Control Group the best characterization. The other features—random assignment, double-blind procedures, and requiring large samples—aren't defining traits of pre-experimental designs: random assignment and blinding are hallmarks of more rigorous experimental designs, and large samples aren’t a defining requirement.

Pre-experimental designs are simple, early-stage setups that lack rigorous control to establish causality. They usually involve a single group that receives the intervention and may have no comparison group or only a nonrandom, non-equivalent one. Without randomization and proper control, threats to internal validity loom, so these designs commonly do not include a true control group. That makes the statement about typically lacking a Control Group the best characterization. The other features—random assignment, double-blind procedures, and requiring large samples—aren't defining traits of pre-experimental designs: random assignment and blinding are hallmarks of more rigorous experimental designs, and large samples aren’t a defining requirement.