## SPSS HOMEWORK 1 INSTRUCTIONS: SINGLE-SAMPLE T-TESTS AND PAIRED-SAMPLES T-TESTS

• SPSS Homework 1 Instructions:

Single-Sample t-Tests and Paired-Samples t-Tests

When submitting this file, be sure the filename includes your full name, course, and section. Example: HW1_JohnDoe_355B03

Part 1:

Note that for all problems in this course, the standard cut-off for a test of significance will be p < .05 unless otherwise noted in the problem.

1.   Single-Sample t-Test (based on Green & Salkind: Lesson 22 – Exercises 1–4, but follow the instructions below instead)

Open the Lesson 22 Exercise File found in Blackboard Course content (under Syllabus and Assignment Instructions>Assignment Instructions>SPSS Homework 1>SPSS Homework 1 Files>Mod1_Lesson 22 Exercise File 1). Always use the Blackboard files instead of the files on the Green and Salkind website, as some files have been modified for the purposes of this course.

1.     A total score variable is included in the data file in Blackboard (“tot_score”), so you do not have to compute it. Use this variable as your dependent variable.

2.     The test value for the single-sample t-test is 2 (1/4 of 8, or the score which a student would achieve by chance). Use 2 as the test value when running the analysis for this exercise.

3.     Conduct a single-sample t-test on the total score variable. Paste the output into your Word document and type in the answers to the following questions underneath the output: (2 pts for output)

a.      Mean algebra score (2 pts)

b.     t-test value (the result of the t-test, not the “test value” which is already given) (2 pts)

c.      p value (significance) of the test (2 pts)

4.     Write a current APA-style Results section based on your analysis. All homework Results sections must follow the example given in the SPSS tutorials and the Course Content document “Writing Results of Statistical Tests in Current APA Format” (note: you do not have to refer to a figure). Remember to include a decision about the null hypothesis. (2 pts)

5.     Create a histogram that demonstrates the distribution of scores. Be sure to correctly label the X and Y axes and give your graph a title. (2 pts)

2.   Green & Salkind: Lesson 23 – Exercises 6–8: (Lesson 23 Exercise File 1)

The following helpful tips are numbered to correspond with the exercise number to which they refer within the Green & Salkind text:

6.     Instead of identifying these values on your output, as the text states, write them into your Word file as written answers for #6 a, b, c, and d. (output = 2 pts; a–d = 2 pts each)

7.     Write a current APA-style Results section based on your analyses. All homework Results sections must follow the example given in the SPSS tutorials and the Course Content document “Writing Results of Statistical Tests in Current APA Format” (note: you do not have to refer to a figure). Remember to include a decision about the null hypothesis. (3 pts)

8.     You will create the boxplot here instead of in the Results section. (2 pts)

Part 2:

1.     A counseling psychologist administers the BDI to a sample of adult clients at the community clinic where he works. The population mean for adults in the general population on the BDI is 6.3. The table below shows the scores the counselor has collected. Using the table, enter the data into a new SPSS file and conduct a single-sample t-test to evaluate whether these BDI scores are significantly different from those of the general population of adults.

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.

BDI Scores

7

9

12

5

21

8

8

5

32

37

6

7

a)     Paste the SPSS output. (2 pts)

a)     Write a current APA-style Results section based on your analyses. All homework Results sections must follow the example given in the SPSS tutorials and the Course Content document “Writing Results of Statistical Tests in APA Format” (note: you do not have to refer to a figure). Remember to include a decision about the null hypothesis. (3 pts)

b)     Create a histogram that demonstrates the distribution of scores. Be sure to correctly label the X and Y axes. (2 pts)

1.     A sports psychologist is studying the efficacy of a new public school health program on the number of minutes 10th graders exercise per week. She surveys a sample of 10th graders before the program begins and records the number of minutes they report exercising per week. After 2 months in the program, the students are surveyed again. The data are listed in the table below. Using this table, enter the data into a new SPSS data file and run a paired-samples t-test to test the claim that the new public health program significantly changes the number of minutes exercised for 10th graders.

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.

Minutes Ex./Wk.

Before Program

Minutes Ex./Wk.

After Program

45

47

50

55

40

42

60

55

35

50

50

50

60

75

60

55

60

80

45

60

a)     Paste the SPSS output. (2 pts)

b)     Create a boxplot comparing the before and after scores. Be sure to correctly label the X and Y axes. (2 pts)

c)     Write a current APA-style Results section based on your analysis. All homework Results sections must follow the example given in the SPSS tutorials and the Course Content document “Writing Results of Statistical Tests in Current APA Format” (note: you do not have to refer to a figure). Remember to include a decision about the null hypothesis. (2 pts)

Submit this assignment by 11:59 p.m. (ET) on Monday of Module/Week 1.