Controlled listening experiments use pilot tests and counterbalanced stimulus orders to tame independent variables

Evidence

Part of the process of planning a controlled experiment is thinking through such aspects (the ones given here are just examples and are not presented as a definitive list) before carrying out a full test. It is common to try a pilot test with a small number of listeners to check the test procedure and for the presence of any additional independent variables. Some inde­ pendent variables can be controlled by ensuring they remain constant (for example, the ventilation might be turned off, and measures could be taken to reduce background noise). Others can be controlled through the test pro­ cedure (for example, any learning effect could be explored by playing the stimuli in a different order to different subjects or asking each listener to take the test twice with the stimulus order being reversed the second time). — David Howard, Jamie Angus, coustics and Psychoacoustics, 2365

Categorization

• SEED: Could ground an essay on how careful experimental design mirrors fair critical reasoning in everyday life.