# PSYC Statistics, Green and Salkind

Part 1:

Green & Salkind: Lesson 31, Exercises 1–4

The following helpful tips are numbered to correspond with the exercise number to which they refer (a dash indicates that no tips are needed):

1. ———- (2 pts for output and 2 pts each for a–c)

2. Answer this question in sentence form. Include the correlation (r) and degrees of freedom, the p value, and whether these values indicate a significant correlation between the variables or not. (2 pts)

3. All homework “Results sections” must follow the example given in the Course Content document “Writing Results of Statistical Tests in Current APA Format” (Note: you do not have to refer to a figure). (2 pts)

4. ———- (2 pts)

Part 2:

1. A clinical psychologist would like to determine whether there is a relationship between observer ratings of children’s anxious behaviors and scores on an established diagnostic interview assessing anxiety disorders. He administers the diagnostic interview to 28 children and records these scores. He then trains an observer to independently rate anxiety-specific behaviors for each of the 28 children. These ratings are totaled for an overall “anxious behavior” score. On both the interview and the behavioral ratings, a higher score indicates higher levels of anxiety. These scores are listed in the table on the following page. Conduct a Pearson correlation coefficient analysis to determine whether there is a relationship between the interview scores and the behavioral ratings for this group of children.

The steps will be the same as the ones you have been practicing in Part 1 of the assignment—the only difference is that you are now responsible for creating the data file as well. Remember to name and define your variables under the “Variable View,” then return to the “Data View” to enter the data. (3 pts)

Interview (Range 0–9)

Anxious Behavior Rating (Range 0–25)

3

7

2

6

4

6

9

21

7

20

7

18

4

10

8

9

3

5

3

7

2

5

1

3

6

17

8

19

8

23

7

22

1

4

2

7

3

7

3

3

5

13

8

20

7

16

4

12

6

13

6

18

5

15

2

9

2. Create a simple scatterplot of the relationship between these variables (define interview scores as the x-axis and behavioral ratings as the y-axis). (3 pts)

3. Write an APA-style Results section describing the outcome. All homework “Results sections” must follow the example given in the Course Content document “Writing Results of Statistical Tests in Current APA Format” (Note: you do not have to refer to a figure). Be sure to include the direction of the relationship between the variables (positive? negative? none?) in your section. (3 pts)

4. A neuropsychologist is assessing the relationship between brain function and performance on a visuo-spatial task. He administers a test to 14 patients on which scores can range from 1–20: a high score indicates normal brain function, and a low score indicates some levels of brain dysfunction. He then asks each patient to complete a maze and records the number of mistakes the patient makes from start to finish. The scores are listed in the table below. Conduct a Pearson correlation coefficient analysis to determine what the relationship is, if any, between brain function and performance on the maze task.

The steps will be the same as the ones you have been practicing in Part 1 of the assignment—the only difference is that you are now responsible for creating the data file as well. Remember to name and define your variables under the “Variable View,” then return to the “Data View” to enter the data. (3 pts)

Dysfunction Score

Number of Mistakes on Maze Task

3

25

8

18

9

18

4

26

15

6

6

19

18

3

17

4

19

6

6

16

5

14

20

2

17

5

5

23

5. Create a simple scatterplot of the relationship between these variables. (3 pts)

6. Write an APA-style Results section describing the outcome. All homework “Results sections” must follow the example given in the Course Content document “Writing Results of Statistical Tests in Current APA Format” (Note: you do not have to refer to a figure). (3 pts)

7. The null hypothesis for this scenario can be written as follows: “There is no relationship between level of brain function and the number of mistakes made on a maze task.” Based on your results, should this hypothesis be rejected or retained, and why? Write your answer in sentence form. (2 pts)

Part 3: Cumulative Homework

1. A developmental psychologist is studying whether students in a certain preschool program perform better than preschoolers in the state in general on a measure of math readiness. The mean score for preschoolers in the state on the measure is 87. The psychologist tests the preschoolers in the program and records the scores in the table below. Choose the correct test to analyze this question, set up the SPSS file, and run the analysis. Follow the directions under the table below.

Math Readiness Scores90

89

86

91

78

92

88

73

79

89

88

91

93

89

92

a) Paste appropriate SPSS output. (2 pts)

b) Paste appropriate SPSS graph. (2 pts)

c) Write a Results section in current APA style describing the outcome. All homework “Results sections” must follow the example given in the Course Content document “Writing Results of Statistical Tests in Current APA Format” (Note: you do not have to refer to a figure). (2 pts)

Submit this assignment by 11:59 p.m. (ET) on Monday of Module/Week 5.