What research method combines legally constructed theory with systematic observation?

The correct answer is the scientific method, as it encompasses a structured approach to inquiry that combines theoretical frameworks with systematic observation and experimentation. The scientific method begins with hypotheses derived from established theories and then employs rigorous observation, measurement, and additional experimentation to test these hypotheses in an empirical way. This method ensures that findings are based on observable, repeatable evidence, allowing researchers to draw conclusions that can be validated and refined further.

In contrast, qualitative research typically emphasizes understanding human behavior and social phenomena through the collection of non-numerical data, focusing more on narrative and subjective experiences than on systematic observation tied directly to theory. Quantitative research, while systematic, primarily involves numerical data and statistical analysis, often lacking the theoretical construction that guides the observations made. Ethnographic studies focus deeply on immersive observation within specific cultures or societal groups, prioritizing descriptive insights over the systematic verification component that characterizes the scientific method. Therefore, the scientific method is the most appropriate answer, as it explicitly merges theory with a structured observational approach to research.