Experimental Design

Experimental design describes the way participants are allocated to experimental groups of an investigation. Types of design include Repeated Measures, Independent Groups, and Matched Pairs designs.

Repeated Measures Design

Where the same participants are allocated to all groups (i.e. take part in all conditions) of an experiment.

Strengths

The results will not be subject to participant variables (i.e. individual differences between participants), putting more confidence in dependent variable changes being solely due to manipulated changes in the independent variable.

As the same participants are used [at least] twice, extra participants do not need to be recruited.

Weaknesses

There is risk of observing order effects (e.g. practice / fatigue effects, or demand characteristics), but this risk be reduced by counterbalancing (i.e. controlling the order of variables so that each order combination occurs the same number of times, e.g. one half of participants partake in condition A followed by…