Answer:

survey research

The questionnaire is the main instrument for collecting data in survey research. Basically, it is a set of standardized questions, often called items, which follow a fixed scheme in order to collect individual data about one or more specific topics. Sometimes questionnaires are confused with interviews.

Questionnaires are used in which method.?. please tell me fast. okay. please. Don't spam. (mail questionare method).

your answer is survey