Which study meets the definition of research with human subjects under federal regulations?

The study that meets the definition of research with human subjects under federal regulations is one that involves direct interaction or intervention with individuals to collect data about their behavior, experiences, or responses. In this case, the experiment assessing mood's impact on problem-solving directly engages participants, likely measuring their moods and their problem-solving abilities in real-time or through interactions. This aligns with the federal regulations that define research involving human subjects as any research that involves a living individual from whom data is collected through intervention or interaction, or through identifiable private information.

The other study types mentioned do not meet this definition because they do not involve direct engagement with human subjects. A survey of historical data does not collect new information from individuals; it analyzes previously gathered information. Similarly, a study focused solely on computer algorithms without any interaction with people does not include human subjects in its methodology. Lastly, a meta-analysis synthesizes findings from previously conducted studies rather than engaging with living individuals for new data, thus also falling outside the definition of research involving human subjects.