Questionnaires; made up of a pre-set list of written questions (or items) to which a participant responds.
Questionnaireadvantages
+ can be distributed to lots of people = gather large amounts of data quickly and researcher need not be present when completed ... reduces the effort involved and makes questionnaires cost effective
+ straightforward to analyse = especially if closed, fixed-choice questions are used ... statistical data can easily be converted to graphs and charts for comparison
Questionnairedisadvantages
-responses may not always be truthful = respondents tend to present themselves in a positive light ... thus social desirability bias is possible
-response bias = respondents may favour a particular kind of response e.g. they always agree ... this means that all respondents tend to reply in a similar way
