What observation technique involves studying one person in depth to reveal universal principles?

The observation technique that involves studying one person in depth to reveal universal principles is the case study. This method allows researchers to explore the complexities of an individual’s experiences, behaviors, or thought processes in great detail. By focusing on a single case, researchers can gain in-depth insights that may apply more broadly to similar cases or to the understanding of human behavior in general.

Case studies are particularly useful when exploring rare phenomena or when a researcher seeks to understand a particular condition or issue in a comprehensive manner, potentially identifying patterns that could be relevant across larger populations. This depth of analysis often reveals insights that might not be captured through more quantitative methods such as surveys or experimental studies.

In contrast, surveys and experimental studies typically gather data from multiple participants but do not provide the same level of detailed, qualitative insight into individual cases, while correlational studies examine relationships between variables without delving deeply into individual circumstances.