Experimental Designs

• Experimental design


  A design in which researchers manipulate an independent variable and measure a dependent variable to determine a cause-and-effect relationship
• Independent groups design


  Participants are allocated to different groups where each group represents one experimental condition
• Repeated measures


  All participants take part in all conditions of the experiment
• Matched pairs


  - A common form of blocking for comparing just two conditions.

  - In some matched pairs designs, each subject receives both conditions in a random order.

  - In others, the subjects are matched in pairs as closely as possible, and each subject in a pair is randomly assigned to receive one of the conditions.
• Random allocation


  Allocating participants to experimental groups or conditions using random techniques
• Counterbalancing


  A method of controlling for order effects in a repeated measure design by either including all orders of treatment or by randomly determining the order for each subject