The list of disadvantages has been lengthened by Sproull, according to whom the interview method is inefficient because:
o respondents sometimes do not give a relevant answer; they may misinterpret or try to bypass the actual question
o respondents often refuse (or feel embarrassed or afraid) to respond to certain questions
o the recall rate may be poor, because respondents may not remember all the relevant points at a given instance
o the information provided may be incomplete (half-truth can be misleading), out of ignorance or for deliberate reasons