‘调查’ (diào chá) is a verb meaning 'to investigate' or 'to conduct a survey.' It combines two characters: 调 (diào), which means 'to examine' or 'to look into,' and 查 (chá), meaning 'to check' or 'to inspect.' Together, they emphasize a systematic, purposeful effort to gather information—whether about people, events, conditions, or opinions. The word implies careful observation, questioning, data collection, and analysis.

This term is commonly used in formal, professional, or academic contexts—such as journalism, public health, market research, law enforcement, or education. It can refer to both field investigations (e.g., visiting sites, interviewing subjects) and desk-based research (e.g., reviewing records or statistics). While it often carries neutral or serious connotations, context determines tone: a health department may '调查' disease outbreaks, while a school might '调查' student lunch preferences. It is rarely used for casual, personal curiosity.