A design where all participants take part in all treatment conditions is

A design where all participants take part in all treatment conditions is (a) Factorial design

(b) Repeated measures design

(c) Replicated design

(d) Pretest-posttest control-group design

✅ Correct option: (b) Repeated measures design

Explanation:

In a repeated measures design, the same participants experience all experimental conditions. This design reduces individual differences and increases statistical power. However, it is vulnerable to order and carryover effects. Counterbalancing is often used to address these threats. Factorial designs involve multiple independent variables, while pretest-posttest designs involve group comparisons.

10 Related PPSC Facts:

Repeated measures use same participants. Individual differences are controlled. Statistical power is increased. Order effects are common. Carryover effects may occur. Counterbalancing is necessary. Fewer participants are required. Practice effects may bias results. Within-subject designs improve efficiency. Washout periods may be used.