A school psychologist wants to test the effectiveness of a new method for teaching reading. She recruits 500 ﬁrst-grade students in District 203 and randomly divides them into two groups. Group 1 is taught by means of the new method, while group 2 is taught by traditional methods. The same teacher is assigned to teach both groups. At the end of the year, an achievement test is administered and the results of the two groups are compared.
(a) What is the response variable in this experiment?
(b) Think of some of the factors in the study. How are they controlled?
(c) What are the treatments? How many treatments are there?
(d) How are the factors that are not controlled dealt with?
(e) Which group serves as the control group?
(f ) What type of experimental design is this?
(g) Identify the subjects.
(h) Draw a diagram similar to Figure 7 or 8 to illustrate the design.