Final answer:
A telephone interview is a suitable interview technique when direct observation of the respondent's behavior is not necessary.
Step-by-step explanation:
The type of interview technique that can be used if it is not necessary for the researcher to watch the respondent to ensure correct procedures are followed or to verify their reactions is a telephone interview. In a telephone interview, the researcher can pose questions to the respondent over the phone without directly observing their behavior. This type of interview is useful when personal presence is not required and the focus is on gathering verbal information.