Measuring Behaviour An Introductory Guide

Study design is fundamental to good science. A poorly designed study will waste time and resources and could produce misleading or uninterpretable results. A good study design aims to minimise random variation and eliminate confounding variables. Correlational studies make use of natural variation in the variables of interest, whereas experimental studies manipulate variables to understand their causal effects on behaviour. There are advantages and disadvantages to both types of study, but experiments uniquely allow inferences about causation. A good experimental design requires subjects to be randomly allocated to experimental groups. Randomisation ensures the generalisability of results and eliminates confounds in experimental studies. Measurements should ideally be made blind to group membership. Blinding minimises biases caused by the conscious or unconscious expectations of the experimenter or subjects. Careful consideration should be given to when behaviour is measured, as time can affect behaviour. Power calculations can be used to determine the appropriate sample size.