According to the ISO 22301 Auditing eBook, there are three types of personal interview, which differ

in terms of the structure, purpose and depth of information to be elicited. They are:

Fully structured interview: This type of interview follows a predefined set of questions that are asked

in a fixed order. The interviewer does not deviate from the script and does not probe for additional

information. The advantage of this type of interview is that it ensures consistency and comparability

of data across different interviewees. The disadvantage is that it may not capture the nuances and

complexities of the interviewee’s responses, and may miss some important information that is not

covered by the questions.

Semi-structured interview: This type of interview has a general outline of topics or questions to be

covered, but the interviewer has the flexibility to ask follow-up questions, clarify ambiguities, and

explore new areas of interest that emerge during the conversation. The advantage of this type of

interview is that it allows for a deeper and richer understanding of the interviewee’s perspectives,

opinions, and experiences. The disadvantage is that it may introduce some variability and bias in the

data collection and analysis, depending on the interviewer’s skills and style.

Unstructured interview: This type of interview has no predetermined agenda or questions, and the

interviewer relies on the natural flow of the conversation to guide the discussion. The interviewer

may use some open-ended prompts or probes to elicit more information, but the interviewee has

the freedom to express whatever they want. The advantage of this type of interview is that it can

reveal unexpected and insightful information that may not be obtained through other methods. The

disadvantage is that it may be difficult to manage, control, and summarize the data, and it may

require more time and resources to conduct and analyze.

Reference: : ISO 22301 Auditing eBook, Chapter 5: Audit Techniques, Section 5.2: Personal Interview,

Page 63-64.

1of30