What skills are needed to be a good Interviewer?

you need to be a good observer, you should also be an attentive listener, should know how to prod the potential employee for more in depth answers, you must also know how to engage the interviewee in intelligent conversation so as not to appear vague and above all you should be well organized.

1. Good interviewing skills (listening without judging, asking clear questions, etc.) Notes: This is a critical skill in both in-depth interviews and focus group moderating. Listening skills cannot be underestimated because if you don’t actively listen to respondents, you won’t be able to probe on the second, third and fourth levels. Listening skills and remembering their responses builds rapport and encourages the respondent to offer more detailed feedback because they know the interviewer or moderator is listening.
2. Right mix of intelligence and common sense Notes: True for most jobs beyond market research.
3. Good voice tone, pacing, pitch and volume Notes: This is often overlooked but it’s a key reason that differentiates the good moderators and interviewers from the bad ones. I’ve seen moderators and interviewers who read directly from their guide and sound robotic, which discourages the group, and I’ve also seen moderators and interviewers who are so lively and upbeat that it turns some of the group participants off. I am not particularly fond of either. Somewhere in the middle might be your best bet.
4. Appropriate combination of critical reasoning skills and imaginative thinking skills Notes: Moderators and interviewers know the objectives of their client beforehand, so if participants are not giving them the in-depth feedback to address those objectives, you often have to think on your feet and get creative to get better responses.
5. Eye for detail and the ability to hold the big picture at the same time
6. Ability to stay genuinely interested (as a person) and completely detached (as a researcher) Notes: I think this was Henderson’s best recommended skill. This is true as both a moderator and an interviewer. You have to be genuinely interested in the discussion and actively listen to ensure the participant feels comfortable and grows trust that they can be forthright in their opinion. Yet, you cannot bias the research through your demeanor. You may build a great rapport with a participant right off the bat, but you need to stick to objectivity. Challenge their thoughts, probe for specifics and remain a researcher throughout the process.
7. Appropriate blend of empathy and neutrality in word and deed
8. Able to think analytically and live without a sense of closure