Which of the following methods would apply to "field research"?

Concept

Research methods can be classified by where and how evidence is collected: from existing sources, from real-world settings, or under controlled conditions.

Field research gathers primary data through direct contact with people, events, or settings; interviews and observations are common field techniques.

Application

A personal interview obtains first-hand responses through direct interaction between the researcher and a participant. It therefore applies to field research.

Contrast

• Analysis of documents uses existing textual or digital sources and belongs to document-based or library research.

• Analysis of historical records uses archived evidence about past events and belongs to library research.

• A small-group study of random behaviour, play, and role analysis is classified as laboratory research in the cited research-method table.

Cross-check

Mapping all four methods to their research settings leaves personal interview as the only field-research method among the offered choices.

Therefore, the answer is personal interview.