According to the federal regulations, which of the following studies meets the definition of research with human subjects?
a study of twenty 4th grade classrooms in which researchers ask the schools to systematically vary the time of day reading is taught, and collect weekly assessments of reading comprehension for each child over a three-month period.

A study of twenty 4th grade classrooms in which researchers ask the schools to systematically vary the time of day reading is taught, and collect weekly assessments of reading comprehension for each child over a three-month period.

Explanation:

This meets all the criteria of the federal regulations on the definition of research with human subject.

answer; validity;