This document discusses questionnaires as a tool for data collection in nursing research. It defines questionnaires as structured self-report instruments used to gather information from subjects through written or verbal responses. The document outlines the key features, types, questions, format, administration, advantages, and limitations of questionnaires. It emphasizes that questionnaires are commonly used in descriptive nursing studies to gather a broad spectrum of information from subjects about facts, beliefs, attitudes, opinions, and knowledge.