Investigative techniques are methods used to gather information and evidence in order to solve a problem or uncover the truth. These techniques can include interviews, where investigators ask questions to gather insights from witnesses or suspects, and surveillance, which involves monitoring a person or location to collect data. Other common techniques include forensic analysis, where scientific methods are applied to physical evidence, and background checks, which involve researching a person's history. Each technique plays a crucial role in fields such as law enforcement, journalism, and research, helping to ensure accurate and thorough investigations.