PSYC 355 SPSS HOMEWORK 1 INSTRUCTIONS SINGLE-SAMPLE T-TESTS AND PAIRED-SAMPLE T-TESTS Part 1: Note that for all problems in this course, the standard...

SPSS Homework 1 Instructions

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

Part 1:

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

Homework files are found in Blackboard Course Content > Syllabus and Assignment Instructions > Assignment Instructions > SPSS Homework 1 > SPSS Homework Files (select the particular number for the module/week you are working on). Always use the Blackboard files instead of the files on the Green & Salkind website as some files have been modified for the purposes of this course.

1. Single-Sample t-Test: Based on Green & Salkind - Lesson 22, Exercises 1–4 (Mod1_Lesson 22 Exercise File 1), but follow the instructions below instead.

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.

1. 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.

1. 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)

1. 1. Mean algebra score (2 pts)

   2. t-test value (2 pts)

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

1. Write a Results section in current APA style based on your analyses. (3 pts)

1. Create a histogram that demonstrates the distribution of scores. Be sure to correctly label the X and Y axes. (3 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. (2 pts for output and 2 pts each for a–d)

7. 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). (4 pts)

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

Part 2:

1. A counseling psychologist administers an interview assessment that screens for possible internet addiction to his adolescent clients who live in a rural area. He assumes that children in this area may exhibit higher scores than children in the general population, who normally score a 25 on a scale of 1–100. 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 or not these adolescents scored higher than the general population.

The steps will be the same as the ones you have been practicing in Part One 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.

1. Paste SPSS output (2 pts)

1. Write an APA-style Results section based on your analyses. All homework “Results sections” should 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)

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

2. A clinical psychologist is studying the differences in the number of Facebook® friends between identical twins raised apart. She believes that twins raised in different environments will have differences in the number of friends, which would help point to the influence of environmental factors over inherited factors on social outcomes. She divides the twins into two groups (“Twin 1” and “Twin 2”), collects the data and creates 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 identical twins raised apart will have a significantly different number of Facebook® friends.

The steps will be the same as the ones you have been practicing in Part One 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.

1. Paste SPSS output (2 pts)

1. 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 APA Format” (note: you do not have to refer to a figure). Remember to include a decision about the null hypothesis. (2 pts)

1. Create a boxplot comparing the twins’ scores. Be sure to correctly label the X and Y axes. (2 pts)

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