Experts Only. Please Use Only the Methods Contained in the Book and Show All Work And

Experts only. Please use only the methods contained in the book and show all work and calculations. Book: Jackson, S. L. (2012) Research methods and statistics: A critical thinking approach. Experts only. Please use only the methods in the applicable chapters. Show all work and calculations. Books: Jackson, S.L. (2012) Research methods and statistics: A critical thinking approach

Chapter 11 , selected even exercises p 308-310 4. If a researcher decides to use multiple comparisons in a study with three conditions, what is the probability of a Type I error across these comparisons? Use the Bonferroni adjustment to determine the suggested alpha level. 10. In a study of the effects of stress on illness, a researcher tallied the number of colds people contracted during a 6-month period as a function of the amount of stress they reported during that same time period. There were three stress levels: minimal, moderate, and high stress. The sums of squares appear in the following ANOVA summary table. The mean for each condition and the number of subjects per condition are also noted. Source Between groups Within groups Total df 22.167 14.750 36.917

Stress Level Minimal Moderate High

Mean 3 4 6

N 4 4 4 a. Complete the ANOVA summary table. b. Is F obt significant at α = .05; at α = .01 c. Perform post hoc comparisons if necessary. d. What conclusions can be drawn from the F -ratio and the post hoc comparisons? e. What is the effect size, and what does this mean? f. Graph the means.

12. A researcher conducted an experiment on the effects of a new drug on depression. The researcher had a control group that received nothing, a placebo group, and an experimental group that received the drug. A depression inventory that provided a measure of depression on a 50-point scale was used (50 indicates that an individual is very high on the depression variable). The ANOVA summary table appears next, along with the mean depression score for each condition. Source Between groups Within groups Total df SS 1,202.313 2,118.00 3,320.313

Drug Condition Mean n Control 36.26 Placebo 33.33 15 Drug 24.13 15

15 a. Complete the ANOVA summary table. b. Is F obt significant at α = .05; at α = .01 c. Perform post hoc comparisons if necessary. d. What conclusions can be drawn from the F -ratio and the post hoc comparisons? e. What is the effect size, and what does this mean? f. Graph the means. 14. A researcher has been hired by a pizzeria to determine which type of crust customers prefer. The restaurant offers three types of crust: hand-tossed, thick, and thin. Following are the mean number of 1-inch pieces of pizza eaten for each condition from 10 subjects who had the opportunity to eat as many pieces with each type of crust as they desired. The ANOVA summary table also follows. Source Subject Between Error Total Crust Type Hand-tossed Thick Thin df

SS 2.75

180.05 21.65 204.45 Mean 2.73 4.20 8.50 n 10 10 10 a. Complete the ANOVA summary table.

F b. Is F obt significant at α = .05; at α = .01 c. Perform post hoc comparisons if necessary. d. What conclusions can be drawn from the F -ratio and the post hoc comparisons? e. What is the effect size, and what does this mean? f. Graph the means.

/////Chapter 12, even exercises pp 335 -337. 2. How many independent variables are in a 4 x 6 factorial design? How many conditions (cells) are in this design? 4. What is the difference between a cell (condition) mean and the means used to interpret a main effect? 6. What is the difference between a complete factorial design and an incomplete factorial design? 8. Explain the difference between a two-way ANOVA and a three-way ANOVA. 10. Complete each of the following ANOVA summary tables. In addition, answer the following questions for each of the ANOVA summary tables: a. What is the factorial notation? b. How many conditions were in the study? c. How many subjects were in the study? d. Identify significant main effects and interaction effects. Source A B Ax B Error Total

1 2 2 30 35

Source A B Ax B Error Total

2 3 6 72 83 df 60 40 90

MS F

390 df 40 60 150 400

Source A B Ax B Error Total

1 1 1 36 39 df 10 60 20

150

12. A researcher is attempting to determine the effects of practice and gender on a timed task. Participants in an experiment are given a computerized search task. They search a computer screen of various characters and attempt to find a particular character on each trial. When they find the designated character, they press a button to stop a timer. Their reaction time (in seconds) on each trial is recorded. Subjects practice for 2, 4, or 6 hours and are either female or male. The reaction time data for the 30 subjects appear here. 2 Hours

Women 12 13 12 11 11

Men 11 12 13 12 11

4 Hours

10 10 10 8 7

8 8 10 10 9

6 Hours

7 5 7 6 7

5 6 8 6 8 Source Gender Practice Gender x Practice Error Total df

SS 0.02 140.60 0.073 28.00 168.70

F a. Complete the ANOVA summary table. Calculate the sums of squares, use the preceding data to do so. b. Is F obt significant at α = .05; at α = .01 c. Perform post hoc comparisons if necessary. d. What conclusions can be drawn from the F -ratio and the post hoc comparisons? e. What is the effect size, and what does this mean? f. Graph the means.

// Chapter 13. Even exercises p 360 2. A psychology professor is interested in whether implementing weekly quizzes improves student learning. She decides to use the weekly quizzes in one section of her introductory psychology class and not to use them in another section of the same course. Which type of quasi-experimental design do you recommend for this study? Why? < Note: this question, #3, is not to be done but provided so that question 4 below can be answered> 3. If the psychology professor in exercise 2 had access to only one section of introductory psychology, describe how she might use a single-group design to assess the effectiveness of weekly quizzes. Which of the three single-group designs would you recommend? 4. Identify some possible confounds in each of the studies you outlined in your answers to exercises 2 and 3. 6. Give three reasons a researcher might choose to use a single-case design. 8. How does a multiple-baseline design differ from a reversal design?