Interviews Alfred Kobsa University of California, Irvine

When to chose an interview… Scope of problem not fully clear, unclear what to ask Questions abstract, open-ended Lots of information / holistic view from a few users needed (vs. little information from many users) Rapid answers not needed Information at a specific location/time needed Broad geographic distribution of respondents not needed Topics are difficult to talk about Anonymity not required O.k. with the fact that the recording of responses is difficult

Steps in preparing an interview Identify the objectives of the study (in writing) Select the type of interview (unstructured, structured, semi- structured, contextualized, in person vs. via phone) Decide how you will analyze the data (transcription?, qualitative analysis software?, statistical tests if any) Formulate questions (avoid overly long, vague, double- barreled, leading or loaded questions, double negatives, and questions that may trigger biases) Write questions down Test your questions Plan on audio-recording answers or using note-taker Plan on interviewing 6-10 participants of each user type

During the interview Keep participants focused, but give them plenty of freedom Give acknowledgements occasionally, to keep participants motivated Provide background information only if necessary Develop some rapport with participants (and ask sensitive questions only thereafter) Don’t provide personal opinions, information about yourself Don’t interrupt participants unless it is important Don’t disagree with participants Don’t put words in their mouths, complete their sentences Allow them to be silent while they are thinking

Problems to consider Social desirability bias ( ☛ phrase questions carefully, use several questions for same concept, go for facts and not habits, attitudes or intentions) Self-image ( ☛ see above) Acquiescence bias ( ☛ phrase questions carefully) Prestige bias ( ☛ phrase questions carefully) Self-incrimination ( ☛ emphasize ordinariness, impunity) Honesty ( ☛ check consistency, ask for details, challenge answers, discard data, blacklist potentially dishonest user)

Recommended phrasing