Probes and Probing

Probing is a specific research technique used by interviewers in individual and group interviews and focus groups to generate further explanation from research participants. Probing may be achieved nonverbally with pauses or gestures, or verbally with follow-up questions. Effective and efficient probing in interviewing relies on the interviewer's ability to actively listen to what interviewees have said and judge if further information is necessary to making meaning from what has been said, and then judiciously probe for further descriptions concerning the topics of interest. Methodologists who provide directions for how interviewers can ask interviewees for further explanation, clarification, or elaboration of their responses agree that mastery of this technique is critical for “good” [Page 682]interviewing—whether using standardized survey protocols or open-ended interview guides.

One of the most extensive discussions of probing in interviewing has been provided by Raymond Gorden, who has outlined seven forms of probing questions that may be used by interviewers to manage the topic of interview talk. The silent probe—in which the interviewer refrains from commenting—allows interviewees to take up the topic of the talk in ways that are meaningful to them and is the least intrusive prompt. However, interviewers must be able to identify when it is useful to pause to allow interviewees to continue, and when participants have completed their turns. In the latter case, if participants are seeking direction from the interviewer, misplaced pauses may interfere with the flow of talk. Encouragement to speakers to continue may be conveyed by head nods, gaze, facial expression, gestures, and words such as “mm” and “uh huh.” Next, particular probes call on interviewees to provide immediate elaboration. For example, interviewers can request further information about the topic by asking questions such as, “Tell me more about that.” “What happened then?” Probes for immediate clarification, in contrast, request further information about particular topics. For example, this could include questions such as, “You mentioned x, tell me who was involved at that time?” or “What happened after you had completed y?” Probes involving retrospective elaboration orient the interviewee to earlier talk and seek further information. For example, the interviewer might begin by stating, “Earlier you mentioned that you were involved in z; thinking back to that time, tell me more about that.” Similarly, probes focused on retrospective clarification seek specific information about earlier talk. For example, “You talked earlier about the very first time you heard about y. Describe that event in detail—Was anyone with you at the time? What was that like for you?” The final form of probe outlined by Gorden is that of mutation. In this kind of probe, the interviewer uses prior talk to expand the topic into a new area. For example, “You've told me how you became involved in z, and what that was like for you. Tell me about your friends' responses to that.”

As Gorden has explained, clarification probes exert more control over the topic than elaboration probes. That is, clarification questions specify the topics that participants should provide further information about; elaboration probes seek more information, while not specifying what kind. Whether interviewers should seek further elaboration and clarification immediately or retrospectively is another question to be considered. Here, general guidelines for good practice are useful: Interviewers should avoid interrupting interviewees, should pose probes using participants' words wherever possible, and, in probing, interviewers should show that they have been actively listening to participants.

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