Experimental Designs

• There are three types of experimental design in Psychology.
• Independent groups/ measures is one type of experimental design.
• Repeated measures is a type of experimental design.
• Matched pairs is an example of an experimental design.
• Independent groups compares the difference between two or more separate groups.
• Independent groups are usually given the same task or activity, before they are compared.
• Independent groups are different people in each group, such as males in one group and females in another.
• Repeated measures design compares the performance from the same group of people, on 2 or more tasks.
• Repeated measures design is subject to order effects (practice and fatigue).
• Repeated measures designs can use counterbalancing to reduce the risk of order effects.
• Repeated measures has less risk of individual differences as people are compared against themselves.
• Independent groups designs have individual differences between the participants in the separate groups.
• Independent groups designs are more time consuming as they require more participants.
• Independent groups allow researchers to compare the difference between people.
• In some experiments the IV is easy to see in the independent groups design.
• Matched pairs design uses similar people in each group, matches them on key characteristics such as age, gender, ethnicity, IQ.
• Matched pairs can be difficult to find participants with similar characteristics.