Roughly ten percent of elementary schools in California have a system whereby 4th to 6th graders share a common classroom and a single teacher (multi-age, multi-grade classroom). a. Suggest an...

Extracted text: Roughly ten percent of elementary schools in California have a system whereby 4th to 6th graders share a common classroom and a single teacher (multi-age, multi-grade classroom). a. Suggest an experimental design that would allow you to assess the effect of learning in this environment. b. Mention some of the threats to internal and external validity C. and how you would attempt to circumvent these.