Using a form -
- People can take their time answering.
- People can misunderstand questions.
- People can make mistakes when answering.
- People may miss out questions.
- People may not return the form.
- You can make sure that people understand questions.
- You can make sure people answer everything.
- It takes a long time
- If you pay an interviewer, it's expensive.
Non-response = when people do not return the form.
You can't just ask another person instead, or…