Data can be collected relatively quickly because the researcher would not need to be present when the questionnaires were completed.This is useful for large populations when interviews would be impractical.The category can be restricted to as few as two options, i.e., dichotomous (e.g., 'yes' or 'no,' 'male' or 'female'), or include quite complex lists of alternatives from which the respondent can choose (e.g., polytomous).Closed questions can also provide ordinal data (which can be ranked).
Lawrence Kohlberg presented his participants with moral dilemmas.
They can be carried out face to face, by telephone, computer or post.
Questionnaires provide a relatively cheap, quick and efficient way of obtaining large amounts of information from a large sample of people.
Closed questions structure the answer by only allowing responses which fit into pre-decided categories.
Data that can be placed into a category is called nominal data.