In-depth interviews can be conducted with individuals or groups. Questions for in-depth interviews must be open-ended and not closed questions which simply require a "yes" or "no" answer. Open-ended questions induce more information from persons being interviewed and this allows researchers to collect more in-depth data. Open-ended question invite subjects to share more elaborate comments and personal opinions. Group interviews allow participants to talk and discuss questions among themselves, providing further insight into the research topic. Statistical, quantitative data may provide a straightforward answer (such as "agree" or "disagree") but it provides little insight into why a participant answered as such, or what aspects of the questions they agreed or disagreed on.
Direct observation is the process of observing something in its natural setting and recording the results. For example, a researcher may sit at the back of a classroom if conducting research into teaching methods, and record results either on an audio recording device or by making notes. Participant observation is when an observer participates in the research, with or without making other people aware of their intentions. Ethical questions may arise during such research due to the potential secrecy. This type of research may be conducted by joining a social or community group.
Semi-structured interviews work in the same way as in-depth interviews but are generally designed to extract certain information from participants. In contrast, in-depth interviews allow participants to comment freely and speak off topic in some cases. The researcher uses a basic structure, such as a few interview questions, and allows the interview to proceed loosely on the structure they have designed. Unstructured interviews do not have any design or structure; the researcher directs the conversation, guiding the participant to comment on the topic they are researching and only occasionally does he ask questions to prompt the participant onto the research topic. Unstructured interviews, however, can easily influence participants to give a biased answer.
Qualitative methods are cost-effective because they do not require expensive equipment or extensive questionnaire printouts. Using a variety of methods or tools, or a variation of different methods, offers insight into the research topic from a variety of perspectives. For example, using participant observation and an in-depth group interview incorporates the perspective of the researcher as well as the experience of participants in a small group. This can be used to support or contrast the researcher's hypothesis. However, multi-method qualitative research tools only use a small sample group and require a skilled researcher who can accurately interpret abstract and sometimes vague results.