A social worker wants to examine methods that can be used to deter truancy. Three hundred chronically truant students volunteer for the study. Because the social worker believes that socioeconomic class plays a role in truancy, she divides the 300 volunteers according to household income. Of the 300 students, 120 fall in the low-income category, 132 fall in the middle-income category, and the remaining 48 fall in the upper-income category. The students within each income category are randomly divided into three groups. Students in group 1 receive no intervention. Students in group 2 are treated with positive reinforcement in which, for each day the student is not truant, he or she receives a star that can be traded in for rewards. Students in group 3 are treated with negative reinforcement such that each truancy results in a 1-hour detention. However, the hours of detention are cumulative, meaning that the first truancy results in 1 hour of detention, the second truancy results in 2 hours, and so on. After a full school year, the total number of truancies are compared.
(a) What type of experimental design is this?
(b) What is the response variable in this experiment?
(c) What are the treatments?
(d) What variable serves as the block?
(e) Draw a diagram similar to Figure 7, 8, or 10 to illustrate the design.