From an earlier project, I had learned of a National Education Association recommendation regarding student to teacher ratio:
NEA recommends an optimum class size of 15 students in regular programs, especially in the early grades, and a proportionately lower number in programs for students with exceptional needs, including children with disabilities and English language learners.
The question I wanted students to investigate is simple: Is there a level that the student to teacher ratio will stabilize to in the long run?
The question is realistic and is generate by a national organization and the data corresponding to this question is completely realistic. Most students enrolled in the class can relate to this question since many of them just graduated from American schools or have children enrolled in American schools.