What type of research is characterized by not collecting identifiers in a study about junk food availability?

In this scenario, the type of research characterized by not collecting identifiers is classified as "not human subjects." This means that the research does not involve collecting personal data from individuals that could identify them, such as names or other identifying information. When identifiers are absent, the data collected can no longer be traced back to specific individuals, which falls outside the regulations governing human subjects research.

Research that doesn't involve human subjects is often more focused on aggregate data or observations that do not require individual identification. This distinction is crucial because it affects the ethical considerations and the level of oversight required for the study. Not collecting identifiers suggests that the research is likely examining patterns or features at a broader level rather than delving into personal or sensitive information about individuals. Consequently, studies categorized as not involving human subjects may have fewer ethical requirements to meet compared to research that directly engages with human participants.