Not really the same. Open ended questionnaires gives the respondent a lot of flexibility to expatiate on a question, but mostly within the context of the particular question being answered. In other words, it is not just a yes/no answer, but an opportunity to provide explanations and shades of opinions. In-depth interviews on the other hand, particularly if it is not structured allow the respondent to veer into other areas related to the question and indeed, to take ownershipo of the process. part of your skill as a qualitative researcher is to be able to guide the interview and to be able to extract the relevant part from your interview transcript.