1. The Brawling Unified School District is having trouble retaining personnel. A previous study indicated that the problem centers around job satisfaction. The district has decided to try several approaches to modify job satisfaction attitudes of its employees. Two different treatments and a control group will be used. The first treatment consists of viewing a 60 minute video tape that shows the many advantages of working in education and includes interviews with a number of satisfied teachers and administrators. The second treatment involves placing the subjects into small discussion groups in which the leader encourages the individuals to talk about the things that bother them about their job and how they might improve their job satisfaction. The group discussion treatment meets for a half hour each week for four weeks.
For each of the following job categories three individuals were selected at random from district personnel: teachers, counselors, principals, central district personnel, and senior district personnel. Individuals within each of the job categories were randomly assigned to one of the two treatments or the control group. In this study, job category is to be considered an extraneous variable.
At the end of the semester, each of the 15 subjects will take a 75 item Report of Job Satisfaction (RJS) scale and the 200 item Individual Education Employee Enjoyment (IEEE) instrument.
Answer each of the following:
1a. Identify the design.
1b. Draw a schematic of this design.
1c. Make an ANOVA summary table including sources of variation and degrees of freedom.
1d. State the assumptions for this design and how they might be verified.
1e. Discuss how you would handle having both the RJS and the IEEE data.
1f. What measure(s) of strength of association are appropriate for this design.
1g. Discuss the difference between statistical significance and strength of association.
2. The English Department chairman at a major west coast university wishes to improve the writing skills of college freshmen. In particular, there are strong concerns involving the writing skills of science majors. 160 freshmen enrolled in English 105 are randomly selected to participate in this study. The subjects are randomly assigned to one of four treatment groups: (g1) traditional classroom teaching (TCT), (g2) TCT and use of an electronic word processor, (g3) TCT, word processing, and use of Homer (an on-line electronic tutor and writing diagnostic aid), and (g4) TCT and individual tutorial sessions with published authors. Each of the four treatment groups have a 50/50 split between males and females. Further, half the subjects in each group are science majors and half are non-science majors. At the beginning and the end of the fall quarter each of the subjects will be asked to write for one hour on any one of six topics. Different but comparable topics are used at the beginning and end of the quarter. Each essay is scored by three graduate teaching assistants and their scores are averaged for each of the two essays.
Answer each of the following:
2a. Identify the design.
2b. Draw a schematic of this design.
2c. Make an ANOVA summary table including sources of variation and degrees of freedom.
2d. State the assumptions for this design and how they might be verified.
2e. Discuss how you would handle having both pre- and post-test data.
3. Six high schools are selected to participate in a study designed to improve math scores. In two of the high schools (A & B) the juniors will receive traditional math instruction. Juniors in two of the schools (C&D) will receive peer assisted instruction. While juniors in the remaining two schools (E&F) will receive computer assisted math instruction. The schools were assigned at random to the treatments. Additionally, each of the schools is racially mixed, with approximately equal Anglo and Latino populations. Interest is focused on the effect of the different treatments and on the effect of ethnic background. At the end of one year of this program all students will take the Multiple Math Proficiency Inventory (MMPI). Further, IOWA Test reading and math scores, from the ninth grade, are available for each subject from their student record.
Answer each of the following:
3a. Identify the design.
3b. Draw a schematic of this design.
3c. Make an ANOVA summary table including sources of variation and degrees of freedom.
3d. State the assumptions for this design and how they might be verified.
3e. How can the IOWA reading and math tests be used?
4. Twenty inner-city and 20 suburban teachers participate in what they thought was a study on training in the scoring of English essays. The study was really concerned with racial bias in grading. Each teacher scored on a 100 point scale, six essays purportedly written by students in a seventh grade English course. Additionally, the teachers were given information about the student's ethnic background (Anglo, Black, Hispanic) and about the student's past performance (above average, below average). There was one paper for each ethnic group and performance condition.
In reality, all the papers were written by graduate research assistants and contained the same number and type of intentional errors. When given to a group of master teachers, all the papers were rated between 78 and 83 using a standard scoring protocol. The six papers were then randomly assigned to ethnic group and performance level conditions. In administering this experiment each teacher received the six papers in a different counter-balanced order. Answer each of the following:
4a. Identify the design.
4b. Draw a schematic of this design.
4c. Make an ANOVA summary table including sources of variation and degrees of freedom.
4d. State the assumptions for this design and how they might be verified.
4e. Why not make the experiment easier by giving all of the essays in the same order?
Linear Statistical Models Course
Phil Ender, 12Feb98