SURVEY RESEARCHEXPANSION BOX 14
Six Categories of Interview Bias- Errors by the respondent. Forgetting, embarrass-
ment, misunderstanding, or lying because of the
presence of others
2.Unintentional errors or interviewer sloppiness.
Contacting the wrong respondent, misreading a
question, omitting questions, reading questions in
the wrong order, recording the wrong answer to a
question, or misunderstanding the respondent
3.Intentional subversion by the interviewer. Pur-
poseful alteration of answers, omission or rewording
of questions, or choice of an alternative respondent
4.Influence due to the interviewer’s expectations
about a respondent’s answers based on the respon-
dent’s appearance, living situation, or other answers
5.Failure of an interviewer to probeor to probe
properly
6.Influence on the answers due to the interviewer’s
appearance,tone, attitude, reactions to answers, or
comments made outside the interview schedule
We may consider interviewers’ physical appear-
ance, age, race, gender, languages spoken, and even
the voice (see interviewer bias discussion later in
this chapter). For example, in a study using trained
female telephone interviewers from homogeneous
social backgrounds, Oksenberg and colleagues
(1986) found fewer refusals for interviewers whose
voices had higher pitch and more pitch variation and
who spoke louder and faster with clear pronuncia-
tion and sounded more pleasant and cheerful. Most
training programs for professional interviewers are
2 weeks long. They usually include a mix of lec-
tures and reading, observation of expert interview-
ers, mock interviews in the office and in the field
that are recorded and critiqued, many practice inter-
views, and role-playing. The interviewers learn
about survey research and the role of the inter-
viewer. They become familiar with the question-
naire and the purpose of questions, although not
with the answers expected.
Although interviewers largely work alone,
researchers use an interviewer supervisor in large-
scale surveys with multiple interviewers. Supervi-
sors are familiar with the location, assist with
problems, oversee the interviewers, and ensure that
work is completed on time. For telephone inter-
viewing, supervisors help with calls, check when
interviewers arrive and leave, and monitor interview
calls. In face-to-face interviews, supervisors check
to find out whether the interview actually took
place. This means calling back or sending a confir-
mation postcard to a sample of respondents. Super-
visors can also check the response rate and
incomplete questionnaires to see whether inter-
viewers are obtaining cooperation, and they may
reinterview a small subsample, analyze answers, or
observe interviews to see whether interviewers are
accurately asking questions and recording answers.
Interviewer Bias
Survey researchers proscribe interviewer behavior
to reduce bias. Ideally, the actions of a particu-
lar interviewer will not affect how a respondent
answers, and responses will not vary from what they
would have been if asked by any other interviewer.
Proscribed behavior for interviewers goes beyond
instructions to read each question exactly as worded,
and interview bias takes many forms (see Expansion
Box 14, Six Categories of Interview Bias).
We are still learning about the factors that influ-
ence survey interviews. We know that interviewer
expectations can create significant bias. Interview-
ers who expect difficult interviews have them, and
those who expect certain answers are more likely to
get them (see Chart 1). Proper interviewer behavior
and exact question reading may be difficult, but
there are many other forms of interview bias.
Interviewer bias can arise from expectations
based on a respondent’s age and race. In a major
national U.S. survey, researchers learned that inter-
viewers regularly coded Black respondents as
being less intelligent and coded younger respon-
dents as both less intelligent and less informed.
Better interviewer training is needed to reduce such
bias in survey results.^66