In mail surveys or phone interviews, this may not be the case. Administrative Issues Last, but certainly not least, you have to consider the feasibility of the survey method for your study. You might prefer to do personal interviews, but can't justify the high cost of training and paying for the interviewers. You may prefer to send out an extensive mailing but can't afford the postage to do so. Some types of surveys take longer than others.
Interviews require interviewers who are motivated and well-trained.
Group administered surveys require people who are trained in group facilitation. Some studies may be in a technical area that requires some degree of expertise in the interviewer. Clearly, there are lots of issues to consider when you are selecting which type of survey you wish to use in your study. And there is no clear and easy way to make this decision in many contexts. There may not be one approach which is clearly the best.