Final answer:
Researchers and investigators use different methods to narrow down the areas to investigate, such as conducting interviews, selecting specific areas, and applying spatial principles for pattern identification.
Step-by-step explanation:
When narrowing down the areas to investigate, researchers and investigators use various methods depending on the specific context.
In the case of medical records and epidemiologists investigating the spread of a disease, they may conduct interviews with a randomly selected sample of patients to gather more information.
In other instances, like in the mapping of galaxies or crime analysis, scientists and analysts use techniques such as selecting a specific area or using spatial principles to identify patterns and narrow down the focus of their investigation.