Questionnaires require relatively little of the evaluator's time, as it falls on the respondent to read through the questionnaire items, interpret them correctly, and write in an answer. Questionnaires can assess a wide range of topics that might be difficult or time-intensive to document in other ways, including teacher classroom practices, attitudes,preferences, and familiarity with concepts or procedures. Because so much of the responsibility for completing questionnaires falls on the respondent, there is the risk that questionnaire items may be misinterpreted, invalidating the response. Respondents may not report their true feelings, practices, or attitudes, particularly if doing so might present them in an unflattering light. Because questionnaires are based entirely upon the interpretation of the respondent, the respondent's possible biases, imperfect recall, and other issues may distort their answers to some degree, in a manner that is outside of their personal control and awareness.
Interviews are a flexible means of information-gathering.
Technology has expanded the media through which interviews can be conducted, so that now an interview can be conducted in an electronic 'chat room' or in a teleconference. Open-format interviews are relatively unstructured. A facilitator, moderator, or interviewer records the participants' statements but does not exert a great deal of control. Interviewees may initially be asked to respond to a general topic or concern, with the later direction of the interview being determined by the participants themselves as they react to points raised in discussion. C losed format.