1. Questionnaires
Advantages
Responses are gathered in a standardised way.
Relatively fast way of gathering information.
Potentially information can be collected from a large portion of a group.
Disadvantages
Low response.
Often will below 50% of postal therefor not representative.
Respondents may not be able to read the question or potentially not understand it.
Answers may be incomplete or irrelevant.
Closed questions limit the response of people views/opinions.
Interviews
Advantages
Response rate is good.
They can help to explain things/answer questions.
This can result in more information.
Good for Facts, comparable data, quantitative data and reduced interviewer bias.
Disadvantages
More expensive training and paying interviews.
Cost increases if the sample is spread over a large area.
Interviewer bias can affect response.
More time consuming than a questionnaire.
Group Interviews
Advantages
Focus groups are becoming more popular
Can produce rich qualitative data
Disadvantages
Individuals can be influenced by the group
Individuals may feel that they haven’t had a chance to give their own view
Individuals may dominate the group interview