Advantages and disadvantages of a questionnaire?

There are both good and bad reasons about using questionnaires as they are cost effective as they are only paper, they are easy to analyse as they can be easily completed with computers that may have a coding system, questionnaires are also very familiar to people as almost every one has completed or looked at one, they also are less intrusive than telephone or face-to-face interviews in which people may feel pressured to answer a question differently because of peer pressure whereas questionnaires are anonymous.

There are two different types of questions that should be used in a questionnaire. There are open questions which give the person answering it a chance to tell us their opinions and reasons and these questions provide qualitative data which is hard to analyse as there are no two answers that will be exactly the same, and there are closed questions which give a multiple choice answer, these type of questions provide quantitative data which is easy to analyse, but these closed questions do not allow the person answering to give in-depth insight and reason behind the choice.