PSYC 355 SPSS Homework 4 : Two-Way ANOVA Assignments

PSYC 355 SPSS Homework 4 : Two-Way ANOVA Assignments

Part One:

Note: For the two-way ANOVA, you will be expected to create a line graph as covered in the SPSS tutorial in the Course Content (and not a boxplot as in the textbook). This applies to future cumulative questions as well. PSYC 355 SPSS Homework 4 : Two-Way ANOVA Assignments.

Green & Salkind: Lesson 26, Exercises 1, 4, 5, 6, 7, and 8

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. Instead of identifying these values on your output, as the text states, please write them into your Word file as written answers for #1 a, b, c, and d. (2 pts for output; a-d = 2 pts each)

4. Produce a line graph instead of a boxplot for this problem. Follow directions in course SPSS tutorial for setting up a line graph. (2 pts) PSYC 355 SPSS Homework 4 : Two-Way ANOVA Assignments.

5. ——- (2 pts)

6. ——- (2 pts)

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

8. Produce a line graph instead of a boxplot for this problem. Follow directions in course SPSS tutorial for setting up a line graph. (2 pts) 

Part Two:

1. A health psychologist is interested in the effects of exercise on stress in people who regularly exercise. Specifically, she is interested in the type of exercise as well as the time of day that the individual exercises. She recruits participants from a local health club who regularly participate in one of three types of exercise: swimming, aerobics, and tennis. She further divides these participants by whether they exercise in the morning or the evening. She then administers a questionnaire to each individual assessing their self-reported stress level. (HIGHER SCORE = HIGHER STRESS). Conduct a two-way ANOVA to analyze these data. Use Tukey’s test in order to conduct any necessary post hoc analyses if there are significant main effects. You do not have to follow up on significant interactions at this time. PSYC 355 SPSS Homework 4 : Two-Way ANOVA Assignments.

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.

Morning	Swimming	Aerobics	Tennis
	10 16 12 16 9	19 21 16 18	17 21 18 14
Evening	14 13 8 12 12	17 12 14 9 10	12 15 19 14

 

1. SPSS output (2 pts, -1 pt if no post hoc test)

2. Write a current 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.For the two-way ANOVA, be sure to include statistical statements concerning the F ratios and p values for both main effects and the interaction, and interpretation statements about all 3 of these effects. (2)  PSYC 355 SPSS Homework 4 : Two-Way ANOVA Assignments.

3. Is there a significant interaction effect? (2)

4. Based on your results, is there one type of exercise that seems more effective in reducing stress than the others? Remember that higher scores = higher stress. (2) PSYC 355 SPSS Homework 4 : Two-Way ANOVA Assignments.

Part 3: Cumulative Homework

1. An investigator in child development research is studying whether parenting styles have an effect on second grade students’ behavior at school. She interviews 25 volunteer families from the same class and separates them into three groups of parenting styles: authoritarian (n = 8); authoritative (n = 8); and permissive (n = 7). Their teacher fills out a behavior inventory for each of the 25 children, and the investigator collects and scores them. The scores are contained in the table below. The scores can range from 0–20, and a higher score indicates more behavior problems. Is there a significant difference between the groups? Choose the correct test to analyze this question, set up the SPSS file, and run the analysis. Follow the directions under the table below. 

Authoritarian	8, 13, 4, 6, 5, 4, 9,12,
Authoritative	8, 5, 6, 4, 2, 5, 10, 13
Permissive	10, 8, 11, 9, 8, 3, 15

 Paste appropriate SPSS output. (4)

Paste appropriate SPSS graph. (4)

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. (4)

PSYC 355 SPSS Homework 4 : Two-Way ANOVA Assignments.

PSYC 355 Homework 5 Correlation

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)

Betsy is interested in relating quality of teaching to quality of research by college professors. She has access to a sample of 50 social science professors who were teaching at the same university for a 10-year period. Over this 10-year period, the professors were evaluated on a 5-point scale on quality as instructors and on quality of their courses. Betsy has averaged these ratings to obtain an overall quality rating as an instructor (rating_1) and the overall quality rating of the courses (rating_2) for each professor. In addition, Betsy also has the number of articles that each professor published during this time period (num_pubs) and the number of times these articles were cited by other authors (cites).

1. Conduct a correlational analysis to investigate the relationship among these variables. Identify the following on the output:

a. p value for the correlation between rating_1 and rating_2.

b. Correlation between cites and num_pubs. c. Correlation between cites and rating_1

2. What is the relationship between the number of articles published and the overall quality of the instructor?

3. Write a Results section based on your analysis of these data. Create a scatterplot matrix to show the relationships among the four variables.

Part 2:

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

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.

Interview (Range 0 to 9)	Externalizing Behavior Index (Range 0 to 25)
3	7
2	9
4	6
9	22
7	20
6	12
4	10
8	9
3	5
4	7
2	5
1	3
6	16
8	19
7	21
7	22
1	4
2	7
3	7
3	3
5	13
8	19
7	16
4	12
3	9
6	18
5	14
3	9

1. SPSS output (2 pts)
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).  (2)
3. 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. For a correlation analysis, also be sure to include the direction of the relationship between the variables (positive? negative? none?) in your section.  (2). PSYC 355 SPSS Homework 4 : Two-Way ANOVA Assignments.

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 to 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.

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

1. SPSS output (2)
2. Create a simple scatterplot of the relationship between these variables.  (2)
3. 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. For a correlation analysis, also be sure to include the direction of the relationship between the variables (positive? negative? none?) in your section.  (2) . PSYC 355 SPSS Homework 4 : Two-Way ANOVA Assignments.

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 reading readiness. The mean score for preschoolers in the state on the measure is 83. 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.

Reading Readiness Scores

90,  78 , 86 , 91 , 78 , 91 , 88 , 72 , 76 , 88 , 88 , 91 , 76 , 89 , 92

1. Paste appropriate SPSS output.  (3)
2. Paste appropriate SPSS graph.  (2)
3. 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) PSYC 355 SPSS Homework 4 : Two-Way ANOVA Assignments.

2. In a study of the relationship between girls’ playtime activities and self-esteem, 16 girls in a fourth-grade class are selected and randomly assigned to one of two groups.  One group plays with a selection of Barbie™ dolls for one hour, and the other group plays with a selection of toy animal figures.  At the end of the hour, the girls are given a verbal interview designed to measure self-esteem. Scores range from 1–12, and higher scores = higher feelings of self-esteem.  Is there a significant difference between the groups on feelings of self-esteem?  Choose the correct test to analyze this question, set up the SPSS file, and run the analysis. Follow the directions under the table below.

Barbie™ Group	4 5 7 9 6 10 4 6 5
Toy Animal Group	8 8 5 11 10 7 7 9

1. Paste appropriate SPSS output.  (2)
2. Paste appropriate SPSS graph.  (2)
3. 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.

PSYC 355 SPSS Homework 4 : Two-Way ANOVA Assignments.

PSYC 355 SPSS Homework 6 Instructions

Prediction: Bivariate Linear Regression

Part 1:

Note: The z-scoring method used in the practice data file is covered in Lesson 19 during PSYC 354.

Green & Salkind: Lesson 33, Exercises 1, 3–4

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. Though the example in the lesson includes creating a z score variable, this step is not necessary for the homework exercises. (3 pts for output and 3 pts each for a–e)
2. Write the answer to the last part of this question beneath your graph, in sentence form. (3 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). Note: The statistical statement for a bivariate linear regression must include at least the equation of the line and the confidence interval for the slope (the second row under Confidence Intervals in the output). (3 pts) .

Part 2:

1. A community psychologist is interested in whether spending time in after-school programs is predictive of the number of arrests as a young adult in a high-risk neighborhood. After collecting records on 17 individuals over 8 years, the psychologist compiles the information listed in the table below. Conduct a linear regression to analyze the research question.

 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)

Table is shown on the following page. 

Hours Spent in After-School Programs	Number of Arrests After Age 17
3	2
41	1
68	1
29	0
7	5
12	4
121	0
54	1
19	3
134	0
106	1
67	1
25	3
73	1
38	4
110	0
31	3

 

1. Construct a scatterplot of the relationship between the 2 variables. Plot the regression line on this graph. (3 pts)
2. Is time spent in after-school programs predictive of the number of arrests as a young adult? 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). The statistical statement for a bivariate linear regression must include at least the equation of the line and the confidence interval for the slope (the second row under Confidence Intervals in the output). (3 pts) PSYC 355 Homework 3 : One-Way ANOVA Assignments.

Part 3: Cumulative Homework

1. To investigate the relationship between hours spent studying and exam scores, researchers measured the following. Is there a significant relationship between hours spent studying and scores? Choose the correct test to analyze this question, set up the SPSS file, and run the analysis. Follow the directions under the table on the following page. PSYC 355 SPSS Homework 4 : Two-Way ANOVA Assignments.

Hours Spent Studying	Exam Scores
1        3        3        4        4        5        5        5        6        6        7        7        8	40      50      51      61      73      71      64      75      68      76      94      85      84

 

1. Paste appropriate SPSS output. (3 pts)
2. Paste appropriate SPSS graph. (3 pts)
3. 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). (4 pts)

Submit this assignment by 11:59 p.m. (ET) on Monday of Module/Week 6. PSYC 355 SPSS Homework 4 : Two-Way ANOVA Assignments.

PSYC 355 SPSS Homework 7 Instructions

Chi Square

Part 1:

Green & Salkind: Lesson 40, 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. Use the method reviewed in the presentation to weight the cases for this data set. (no points—done in data file)
2. Do a, b, and c. (2 pts for output and 2 pts each for a–c)
3. ———- (2 pts)
4. 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) PSYC 355 – Psychotherapy Theory and Research Assignments.

Green & Salkind: Lesson 41, Exercises 1–3

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

NOTE: This exercise does not use the weighted cases method. Use the data file “as is.”

1. Do a, b, c, d, and e. For letter “e,” this question is asking specifically about effect size. (2 pts for output and 2 pts each for a–e)
2. ———- (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)

Part 2:

1. An industrial/organizational (I/O) psychologist is helping a company determine the type of work stations preferred by its employees. The business owner believes that people who work in different departments may prefer different work station layouts. In order to examine this claim, the I/O psychologist sets up 3 simulated work stations: private office (PO), semi-private office (SPO), and open floor plan (OFP). She recruits employees from 3 different departments: Information Technology, Human Resources, and Marketing. The participants spend 30 minutes in each simulated work station performing general pre-arranged tasks. At the end of the 1.5 hours, the participants turn in a form on which they mark which work station they prefer. The results are listed in the table on the following page. Perform a chi square test of independence (using an SPSS two-way contingency table analysis) to determine whether the proportions of work station preferences differ across departments. Use the weighted cases method. PSYC 355 Homework 3 : One-Way ANOVA Assignments.

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. (2 pts)

	Private Office	Semi-Private Office	Open Floor Plan	TOTAL
Information Technology	9	6	4	19
Human Resources	6	10	3	19
Marketing	7	3	9	19
TOTAL	22	19	16	57

 

2.  Create a clustered bar graph depicting your results. (2 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). (2 pts)

Part 3: Cumulative Homework

1. A researcher wants to find out if the number of absences from a chemistry class are predictive of final exam scores at a local university. The data from the past term are in the table below. Are number of absences predictive of final exam scores? Choose the correct test to analyze this question, set up the SPSS file, and run the analysis. Follow the directions on the following page. PSYC 355 Homework 2 – Independent Samples t-Tests

Number of Absences	Final Exam Scores
1        1        2        3        4        5        5        5        6        6        6        7        7	98 95 89 89 80 85 80 75 76 69 70 62 60

1. Paste appropriate SPSS output. (2 pts)
2. Paste appropriate SPSS graph. (2 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). (2 pts)

Submit this assignment by 11:59 p.m. (ET) on Monday of Module/Week 7.

PSYC 355 SPSS Homework 4 : Two-Way ANOVA Assignments

PSYC 355 SPSS Homework 8 Instructions

Part 1

1. Mann-Whitney U Test

This research scenario will be familiar to you. Do letters a, b, and c, answering the questions beneath your SPSS output. (3 pts for output and 2 pts each for a–c)

Nonparametric Tests

Part 1:

1. Green & Salkind: Lesson 42, Exercises 1, 3–4

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. This research scenario will be familiar to you. Do letters a, b, and c, answering the questions beneath your SPSS output. (3 pts for output and 2 pts each for a–c)

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). (4 pts)

4. Create a boxplot as done in earlier modules/weeks. (3 pts) PSYC 355 – Psychotherapy Theory and Research Assignments.

2. Spearman Rho Exercise: This exercise is not found in Green & Salkind. Open the data file “Mod8_SpearmanRho_Exercise File” in the Module/Week 8 SPSS Assignments folder in Blackboard and read the following information; answer the questions below.

Scenario: During the Vietnam War, a draft was put in place that selected young men born on certain dates and placed them in the armed services. The process proceeded via lottery: Dates like “Sept. 14” were placed in capsules, one for each of the 365 days of the year, and the capsules were then drawn randomly from a container. In the 1970 draft, Sept. 14 was the first date drawn, meaning that all young men born on Sept. 14 were eligible for the very first round of the draft, and so on. After the results of the 1970 draft were analyzed, many statisticians and politicians asserted that the process had not been random at all, and certain men had a higher chance of being drafted than others. This case is famous, making it to the pages of international newspapers and the U.S. Supreme Court.

In the SPSS data file in Blackboard, you will find the original 1970 draft data with two variables. Column 1 contains the consecutive day of the year (1 = Jan. 1; 2 = Jan. 2; and so on). Column 2 contains the draft rank (1 = first date drawn; 2 = second date drawn; and so on). So, in the first row of the data set, Day 1 (Jan. 1) had a draft rank of 305. The lower the draft rank, the sooner and more likely a man was to be drafted. So, a higher rank (like 305, for example) was preferable to those who did not want to be drafted right away.

If the process had been statistically random, there would be no correlation between the day of the year you were born and the rank that was assigned to you (r = 0). Any type of significant correlation would mean that there was something relating the variables beyond mere random error, or chance.

1. Open the data file and perform a Spearman correlation analysis for the day of year and the draft rank. Paste your output in the homework document. (2 pts)

2. Write a current APA-style results section describing the outcome. (2 pts)

3. Answer the next two questions in “layman’s terms” as if for someone who does not know much about statistics: (a) Why did people accuse the process of not being random? (b) What do the data indicate for men born earlier in the year vs. men born later in the year? (2 pts) PSYC 355 – Psychotherapy Theory and Research Assignments.

It’s not required, but if you want to check out the original New York Times article and see an interesting graph, go to this link:http://frewm.wikispaces.com/file/view/nytimes.pdf

(Data file source: http://www.amstat.org/publications/jse/v5n2/datasets.starr.html#rosenbaum1)

Part 2:

1. A university assessment department collects data to determine whether university rankings differ based on their regional location. Some rankings are missing because the universities ranked at that level were in different regions than those of interest to the department. Based on eight universities in each of two different regions, is there a difference between university rankings based on their regional locations? Perform a Mann-Whitney U test, being sure to follow the directions under the table. (3 pts)

West Coast	East Coast
	2 5 6 12 16 17 18 19	1 3 4 7 8 10 13 15

Note: Your file must be set up in the same manner as the example data file and the exercise file from Part 1, with a grouping variable and a dependent/test variable. Because these are rankings, they are ordinal data and must be identified as such in “Variable View” under the column “Measure.” Click in the cell under “Measure” in the row for your university rank variable, and choose “Ordinal.” This ensures that SPSS treats the data at the proper level of measurement.

2. Create a boxplot depicting the results. (3 pts)

3. 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) PSYC 355 Homework 2 – Independent Samples t-Tests.

Part 3: Cumulative Homework

1. A political pollster is curious about the effects of a town hall meeting on people’s intentions to support a state proposition that would legalize gambling. He interviews people as they leave and asks them whether their opinion about the proposition has changed as a result of the meeting. He records these frequencies in the table below. Choose the appropriate test to analyze this data, and follow the directions below the table.

Less likely to support

No change

More likely to support

PSYC 355 Exam 1 Liberty University Answers

1. The paired-samples t test has three assumptions, including all but:
2. The correct formula for effect size using Cohen’s d for a single-sample t test is:
3. A study by Bettmann (2007) published in the Journal of the American Psychoanalytic Association assessed whether the attachment relationships between adolescents and their parents change as a result of a residential wilderness treatment experience for the adolescents. Participants completed the Adolescent Attachment Questionnaire at the start and at the end of the wilderness program. Which statistical test would we use to determine whether the wilderness treatment affected attachment relationships?
4. For an independent-samples t test, there were 8 participants in Group 1 and 11 participants in Group 2. The total degrees of freedom were:
5. The single-sample t test compares a sample mean to a population mean when:
6. A clinical researcher was interested in determining whether his interventions were effective in minimizing depression symptoms among his participants. To assess the effectiveness of his treatment program, he administered a depression inventory prior to his treatment and after his treatment. He hypothesized that depression scores would be lower at time two compared to time one. He then compared the mean differences between the two groups and found that his treatment was effective. The dependent variable in this study is:
7. When scientists call a hypothesis test conservative, they mean that it is:
8. The formula for the degrees of freedom for the single-sample t test is:
9. A p level of 0.05 corresponds to a confidence interval of ________%.
10. The formula for the research hypothesis for a paired-samples t test is:
11. The appropriate symbolic representation of corrected variance for a sample is:
12. The comparison distribution for an independent-samples t test is a distribution of:
13. Which of the following statements is true about the assumptions of the independent- samples t test?
14. The critical cutoffs for a two-tailed, paired-samples t test with seven participants at a p level of 0.01 are:
15. Which of the following reports of statistical results are in appropriate APA format?
16. The critical cutoff(s) for a two-tailed, paired-samples t test with 23 participants at a p level of 0.05 is (are):
17. A clinical researcher was interested in determining whether his interventions were effective in minimizing depression symptoms among his participants. To assess the effectiveness of two of his treatment programs, he administered a depression inventory after his treatment for two different groups of clients, each receiving a different treatment. He hypothesized that depression scores would be different between the two groups. The researcher’s hypothesis is:
18. The numerator (top portion) of the ratio for calculating all the t statistics contains:
19. If the standard deviation for a population, as estimated from a sample, is s = 10.23, then the standard error for a sample size of N = 20 is:
20. In an independent-samples t test, how is the research hypothesis symbolized?
21. The appropriate hypothesis test to use for a between-groups design with two groups is a(n):
22. In a(n) ________, one sample is compared to a population for which we only know the mean during hypothesis testing. PSYC 355 – Psychotherapy Theory and Research Assignments.
23. Which of the following illustrates the APA format for reporting statistically significant results for an independent-samples t test?
24. A researcher studies 45 volunteer citizens from a small community and asks them about the amount of caffeine (in milligrams) they ingest before and after lunch each day. The null hypothesis for this paired-samples study could be:
25. A researcher investigates if the extent to which people care about keeping their house clean and neat changes if they are given new things in that home. He follows eight families that were selected to receive home makeovers, assessing their cleanliness before the makeover and after. Given the following confidence interval [–1.26, 0.95], make a decision about the hypotheses.
26. Why do we divide by N – 1 rather than by N when estimating a population standard deviation from the sample standard deviation?
27. According to the null hypothesis, the mean difference for the comparison distribution in a paired-samples t test is:
28. In a(n) ________, each participant is assigned to only one group in order to compare mean differences.
29. Unnithan, Houser, and Fernhall (2006) were interested in whether playing the game Dance Dance Revolution (DDR) affected the heart rate of overweight and nonoverweight adolescents differently. A group of 22 adolescents, 10 classified as overweight and 12 as not overweight, played DDR for 12 minutes, during which time the researchers measured each participant’s heart rate. Which statistical test should the researchers use to analyze their data?
30. Twenty people participate in a weight-loss program for two months. Their weights after the two months are compared to their starting weights. What kind of mean difference might we expect if the null hypothesis is true for a paired-samples t test? PSYC 355 Homework 2 – Independent Samples t-Tests.
31. A clinical researcher was interested in determining whether his interventions for depression were effective in minimizing depression symptoms among his participants. To assess the effectiveness of his treatment program, he administered a depression inventory prior to his treatment and after his treatment. He hypothesized that depression scores would be lower at time two compared to time one. He then compared the mean of the differences between the two groups to a known standard and found that his treatment was effective. Which statistical test was the researcher most likely to have used to test his hypothesis?
32. Identify the formula for the single-sample t test.
33. When performing a single-sample t test, an effect size of 0.80 would be interpreted as a:
34. For the single-sample t test, the confidence interval is centered around the:
35. To determine our critical values or cutoffs for an independent-samples t test, we use:
36. A researcher collects 15 data points that yield a mean of 9.164 and a standard deviation (based on N – 1) of 2.377. What is the standard error for the distribution of means?
37. A study found statistically significant results for a hypothesis tested with an independent-samples t test. The author of the study reported her effect size for the test as 1.24. What is true of the two sample means? PSYC 355 – Psychotherapy Theory and Research Assignments.
38. In a paired-samples test, the comparison distribution is a distribution of:
39. A researcher conducts a single-sample t test and finds statistical significance at the 0.01 level. The effect size is then calculated and found to be 0.04. What might you conclude about the findings?
40. The second step in conducting the single-sample t test involves ________ and
41. In a paired‐samples test, the comparison distribution is a distribution of:
42. For an independent‐samples t test, there were 8 participants in Group 1 and 11 participants in Group 2. The total degrees of freedom were:
43. Twenty college students experience the effects of alcohol on reaction time. They perform very basic timed responses in a driving simulator both before and after consuming several alcoholic beverages. The researcher collects a reaction time result for each of the 20 students before and after intoxication, for a total of 40 measures. What are the degrees of freedom for this study?
44. A researcher studies 45 volunteer citizens from a small community and asks them about the amount of caffeine (in milligrams) they ingest before and after lunch each day. The null hypothesis for this paired‐samples study could be:
45. In addition to reporting the results of statistical hypothesis testing, it is also recommended that researchers to report:
46. When we know the population mean but not the population standard deviation, which statistic do we use to compare a sample to the population? PSYC 355 – Psychotherapy Theory and Research Assignments.
47. When performing a single‐sample t test, an effect size of 0.80 would be interpreted as a:
48. As the sample size becomes smaller, the t distributions become:
49. We have learned three t tests, including all of the following except:
50. The comparison distribution for an independent‐samples t test is a distribution of:
51. A study found statistically significant results for a hypothesis tested with an independent‐samples t test. The author of the study reported her effect size for the test as 0.82. According to Cohen’s convention, this effect size is considered:
52. The two populations compared in an independent‐samples t test include the:
53. Which of these is NOT an assumption of the paired‐samples t test?
54. The formula for the degrees of freedom for the dependent‐samples t test is:
55. A psychologist is interested in whether working memory is influenced by sleep loss. The psychologist administers a measure of working memory to a group of subjects at 8 A.M. on Day One of the study and then again at 8 A.M. on Day Two of the study, after keeping the subjects awake the entire night. Does sleep loss affect working memory? What is the statistical analysis we would perform to answer this question?
56. The formula for the research hypothesis for a paired‐samples t test is:
57. According to the null hypothesis, the mean difference for the comparison distribution in a paired‐samples t test is:
58. In a paired‐samples t test, the null hypothesis posits that the mean of the comparison distribution is:
59. The formula for the degrees of freedom for the single‐sample t test is:
60. A study by Bettmann (2007) published in the Journal of the American Psychoanalytic Association assessed whether the attachment relationships between adolescents and their parents change as a result of a residential wilderness treatment experience for the adolescents. Participants completed the Adolescent Attachment Questionnaire at the start and at the end of the wilderness program. Which statistical test would we use to determine whether the wilderness treatment affected attachment relationships? PSYC 355 – Psychotherapy Theory and Research Assignments.
61. A clinical researcher was interested in determining whether his interventions were effective in minimizing depression symptoms among his participants. To assess the effectiveness of two of his treatment programs, he administered a depression inventory after his treatment for two different groups of clients, each receiving a different treatment. He hypothesized that depression scores would be different between the two groups. The researcher’s hypothesis is:
62. s2pooled is the symbol for:
63. Which of the following illustrates the correct APA format for reporting statistically significant results for an independent‐samples t test?
64. Which example best illustrates APA’s standards for reporting descriptive statistics for an independent‐samples t test?
65. For the single‐sample t test, the confidence interval is centered around the:
66. The formula for the total degrees of freedom for the independent‐samples t test is:
67. The mean of the comparison distribution for the null hypothesis of an independent‐ samples t test is:
68. The appropriate symbolic representation of corrected variance for a sample is:
69. The formula “H0: μ1 = μ2” is used to represent the:
70. In a(n) ________, one sample is compared to a population for which we only know the mean during hypothesis testing.
71. Mehl (2007) published in the journal Science the results of an extensive study of 396 men and women comparing the number of words uttered per day by each sex. Which statistical test should Mehl use to analyze the data?
72. The critical cutoffs for a two‐tailed, paired‐samples t test with seven participants at a p level of 0.01 are:
73. The numerator (top portion) of the ratio for calculating all the t statistics contains:
74. The formula for the null hypothesis for a paired‐samples t test is:
75. A psychologist is interested in whether working memory is influenced by sleep loss. The psychologist administers a measure of working memory to two groups of subjects. The subjects in one group were kept awake for the entire night and the subjects in the other group maintained their normal sleep schedules. Which statistical analysis would we perform to answer the question “Does sleep loss affect working memory?” PSYC 355 SPSS Homework 4 : Two-Way ANOVA Assignments.
76. A p level of 0.05 corresponds to a confidence interval of ________%.
77. According to the null hypothesis, the mean difference for the comparison distribution in a paired‐samples t test is:
78. To determine our critical values or cutoffs for an independent‐samples t test, we use:
79. If the standard deviation for a population, as estimated from a sample, is s = 10.23, then the standard error for a sample size of N
= 20 is: