Interviewing groups has the advantage of not separating group members, so families are more likely to agree to participate. Also, the responses they give, as a group, reflect the actual learning when the group members were jointly engaged in activity. One disadvantage of group interviews is that one member may dominate (typically an adult), and group members will often fall into agreement with each other’s opinions. A way to reduce this tendency is to question members individually but in inverse order of status. However, some researchers feel that unequal power dynamics are likely to be representative of the learning dynamic, and therefore interviews with asymmetrical participation are authentic. Group interviews also present the problem of how to quantify data from groups of different sizes, particularly if the study attempts to characterize frequencies of responses. Some researchers code response frequencies into 3 categories: “1,” “2,” and “many.” Finally, although group interviews are more relaxing for participants, there is rarely time to ask all questions equitably before the group becomes restless, so most persons in the group typically do not complete the interview. Alternatively, interviews conducted from a more qualitative or naturalistic perspective may allow for a much looser participation structure by the group members, but they require extended and careful analysis by the researcher afterward.
Because informal environments emphasize learning by choice, using random assignment of learners to treatment and control groups may sometimes be logistically impossible, upsetting to the learners, threatening to the study validity, or all of the above. In such cases, it may be desirable to reference a comparison group that is not a strict control but that provides some sense of plausible baseline behavior (data from visitors to other museums or exhibitions, literature that cites common knowledge, behaviors, or attitudes to a topic, etc.).
With increasing interest in such process-based outcomes as engagement, conversations, and actions, research in informal environments has made increasing use of recording systems, such as audio- and videotape. These raise technical and ethical issues. Technically, the main challenge is often to obtain audio of sufficiently high quality to hear what people are saying above the ambient noise. Attempts at solution include using a Dictaphone (Borun, Chambers, and Cleghorn, 1996), wearing of cordless microphones (e.g., Leinhardt and Knutson, 2004), or placement of microphones on individual exhibits (e.g., Gutwill, 2003). The ethical issues, namely the need to have visitors give informed consent to being recorded, have been addressed by posting signs, augmenting posting-signs (Gutwill, 2003), asking for consent