A statistics professor is designing a new instructional program for graduate students in the doctorate of education program. She has at her disposal computer programs, videos, textbooks, lectures, and group activities. She wants to find out which of these approaches to use and in what combination. To do this, she decides to randomly assign the six sections of statistics, four educational statistics courses and two advanced statistics courses that she teaches to a treatment. Two sections will be taught the unit on descriptive statistics using the lecture-textbook approach, two sections will be taught the unit on descriptive statistics using a combination of the lecture-textbook approach and a computer program approach, and two sections will be taught the unit on inferential statistics using a computer program. She can then see which has the better effect on the unit exam and be guided accordingly-or can she?

Discuss the following problems. Don't repeat information that was posted previously to yours. For ex, if someone already posted the research problem, don't re-report it. Respond with a critique to your peer. What is the research problem?

1. What is (are) the null and research hypothesis (as)?
2. What are the independent and dependent variables? Variables of interest? Covariates?
3. What major threats to internal validity?
4. What major threats to external validity?