Before you choose the method that you’ll use to collect data, you need to think about the population you are studying (e.g. the group of visitors to your museum or online exhibition) and what amount of data (the sample) will be representative enough so you can report what you learn with confidence.
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Normally people say that 10% is a good sample, as long as the 10% is a heterogenous homogeneous population (that is to say, a group made of people with the same backgrounds, experiences, age, for example). This is likely to be the case if you focus on a target population, but less likely if you focus on a general population. With more homogenous heterogeneous groups you need a bigger sample size.
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Select members of the population at a regular interval that you agree in advance. For example, we would survey every 10th person in a list of ENA members arranged alphabetically.
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