Oral surveys have the following benefits...
Reach a large number of people in a relatively short time
Calling a list of stakeholders can take only a few minutes per call depending on the length of the survey
Relatively inexpensive (can be done with trained volunteers)
Survey must be well designed to assure consistency
Data easy to summarize and report
Answers can be entered directly into a data base
High level of return
Reach most of the people on your list
Does not depend on reading proficiency
Volunteers do the reading for the participant
Good for information that requires sequencing
Close-ended questions sequence easily
Interviewers can clarify questions
Assures understanding on the part of the participant
Can indicate strength to which something is felt
Participant may expand on a topic interviewer can note the tone
Easily adaptable to a wide variety of environments
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