Which of the following studies meets the definition of research with human subjects according to federal regulations?

In the context of research regulations, a study that qualifies as involving human subjects is defined as research that involves a systematic investigation designed to develop or contribute to generalizable knowledge and that involves obtaining data about living individuals.

The study involving 20 4th grade classrooms collecting weekly assessments over three months meets this definition because it directly collects data from individuals (the students in the classrooms) and is intended to draw conclusions about human behavior or experiences, thereby contributing to generalizable knowledge regarding that demographic. This engagement with living individuals in a structured and systematic manner is a key factor in identifying the study as involving human subjects.

The other options do not meet the criteria. The college student survey, while it involves human subjects, is not necessarily framed in the same structured and systematic manner required for educational assessments of a broader population, as it may lack a defined methodology about student experiences. The study on temperature preferences of laboratory mice involves non-human subjects entirely, while the retrospective study analyzing public health records does not involve interaction or the collection of data from living individuals directly, which is essential for classification as research with human subjects. Thus, the correct choice aligns with the federal definition specifically due to its focus on active data collection from living individuals in an educational setting.