In which type of research do scientists execute experiments and collect their own data?

Primary research is defined by the direct involvement of scientists in executing experiments and collecting their own data. This type of research is foundational in fields such as nutrition, as it allows researchers to obtain original data tailored to their specific hypotheses or questions. In primary research, experiments are designed, controlled, and executed by the researcher, leading to findings that are fresh and unprocessed by previous analyses.

This form of research includes methodologies such as randomized controlled trials, cohort studies, and laboratory experiments, where the investigator actively engages with the subject matter to determine outcomes, relationships, or behavioral patterns. The emphasis on collecting firsthand data sets primary research apart as it provides a more accurate and direct insight into the phenomena being studied.

In contrast, anecdotal research relies on personal accounts and observations, offering limited generalizability. Secondary research involves analyzing data already collected by others, which lacks the immediacy and context of primary data. Observational research, while it does involve data collection, typically does not include manipulation of variables like experimentation does, further distinguishing it from primary research.