Experimental Designs

• Matched Pairs is where pairs of participants are matched based on relevant variables and then randomly assigned to one of two conditions
• Independent Groups is where two different groups participate in one condition each
• Repeated Measures is where the same group of participants participate in both conditions
• Counterbalancing is used in repeated measures design in order to reduce order effects (ABBA technique)
• Independent groups design does not have order effects
• Independent groups design requires a large amount of people
• Repeated measures removes individual differences
• Repeated measures design is time-consuming
• Matched pairs design controls individual differences
• Matched pairs design does not have order effects
• Matched pairs design is time-consuming and difficult to do accurately
• Quasi-experimental designs seeks to evaluate the casual relationships between variables but without full control over the independent variable
• Non-equivalent control group design is a quasi-experimental design where two groups of participants are selected that are similar in every way except for the independent variable and one group receives experimental treatment while the other is a control
• Interrupted Time-Series design is a quasi-experimental design where data is collected on the dependent variables over a period of time both before and after an intervention to determine whether there was a significant change
• Pretest-Posttest design is a quasi-experimental design where the dependent variable is measured before and after an intervention (without a control group)
• A debrief must include the aim of the study and information about the other experimental group