Which of the following scenarios would be classified as research with human subjects?

The scenario involving a developmental psychologist videotaping interactions among toddlers and caregivers is classified as research with human subjects because it involves direct interaction and observation of individuals who are identifiable, which qualifies as involving human subjects under ethical research guidelines. In this case, the research is focused on the behaviors and interactions of living people, which necessitates considerations for informed consent, confidentiality, and the potential impact on the participants.

Analyzing existing literature does not involve human subjects, as it deals solely with previously published research and data. In the case of a psychologist conducting interviews for a case study, while it does involve human subjects, it lacks the broader interaction that typically qualifies for more comprehensive ethical considerations seen in larger research contexts. Similarly, distributing a survey anonymously online does not involve identifiable individuals in the research process, which changes the ethical implications and typically would not fall under the same scrutiny as research involving direct human interaction.