# PSY 315 Entire Course

PSY 315 Entire Course

STATISTICAL REASONING IN PSYCHOLOGY

PSY 315 Week 1 Practice Worksheet

Complete the University of Phoenix Material: Week 1 Practice Worksheet.

Click the Assignment Files tab to submit your assignment.

Week 1 Practice Worksheet

Provide a response to the following questions. Written responses should be at least 30 to 45 words each.

Explain and provide an example for each of the following types of variables:

Nominal:

Ordinal:

Interval:

Ratio scale:

Continuous:

Discrete:

Quantitative:

Qualitative:

The following are the speeds of 40 cars clocked by radar on a particular road in a 35 miles-per-hour zone on an afternoon:

30, 36, 42, 36, 30, 52, 36, 34, 36, 33, 30, 32, 35, 32, 37, 34, 36, 31, 35, 20

24, 46, 23, 31, 32, 45, 34, 37, 28, 40, 34, 38, 40, 52, 31, 33, 15, 27, 36, 40

Create a frequency table and a histogram. Then, describe the general shape of the distribution.

Raskauskas and Stoltz (2007) asked a group of 84 adolescents about their involvement in traditional and electronic bullying. The researchers defined electronic bullying as “…a means of bullying in which peers use electronics (such as text messages, emails, and defaming Web sites) to taunt, threaten, harass, and/or intimidate a peer” (p. 565). The table below is a frequency table showing the adolescents’ reported incidence of being victims or perpetrators of traditional and electronic bullying.

Using the table below as an example, explain the idea of a frequency table to a person who has never taken a course in statistics.

Explain the general meaning of the pattern of results.

Incidence of Traditional and Electronic Bullying and Victimization (N = 84)

Forms of bullying

N

%

Electronic victims

41

48.8

Text-message victim

27

32.1

Internet victim (websites, chatrooms)

13

15.5

Camera-phone victim

8

9.5

Traditional victims

60

71.4

Physical victim

38

45.2

Teasing victim

50

59.5

Rumors victim

32

38.6

Exclusion victim

30

50

Electronic bullies

18

21.4

Text-message bully

18

21.4

Internet bully

11

13.1

Traditional bullies

54

64.3

Physical bully

29

34.5

Teasing bully

38

45.2

Rumor bully

22

26.2

Exclusion bully

35

41.7

Describe whether each of the following data words best describes descriptive statistics or inferential statistics. Explain your reasoning.

Describe:

Infer:

Summarize:

Compare the three types of research methods and statistics.

Regarding gun ownership in the United States, data from Gallup polls over a 40-year period show how gun ownership in the United States has changed. The results are described below, with the percentage of Americans who own guns given in each of the 5 decades.

Year

%

1972

43

1982

42

1992

48

2002

40

2012

43

Are the percentages reported above an example of descriptive statistics or inferential statistics? Why?

Based on the table, how would you describe the changes in gun ownership in the United States over the 40 years shown?

Refer to the Simpson-Southward et al. (2016) article from this week’s electronic readings. Was this an example of inferential statistics and research or descriptive statistics and research? Justify your response.

PSY 315 Week 2 Practice Worksheet

Complete the Week 2 Practice Worksheet.

Use Microsoft® Virtual Academy for any help using Microsoft® Excel®.

Select the Assignment Files tab to submit your completed worksheet.

Week 2 Practice Worksheet

Provide a response to the following prompts.

The Wilcox & Keselman (2003) article from this week’s electronic readings discusses two problems with measures of central tendency: skewness of the data and outliers. Discuss each of these issues and how they affect measures of central tendency.

How do the sample mean and the population mean differ? What is the symbol for each type of mean?

An expert reviews a sample of 10 scientific articles (n = 10) and records the following numbers of error in each article: 0, 4, 2, 8, 2, 3, 1, 0, 5, and 7.

Compute the mean, median, mode, sum of squares (SS), the variance, and the standard deviation for this sample using the definitional and computational formulas. You may use Microsoft® Excel® data anlysis to compute these statistics and copy your output into this worksheet.

Explain, to a person who has never had a course in statistics what you have done.

Note the ways in which the means and standard deviations differ, and speculate on the possible meaning of these differences, presuming they are representative of U.S. governors and large corporations’ CEOs in general.

A researcher records the levels of attraction for various fashion models among college students. He finds that mean levels of attraction are much higher than the median and the mode for these data.

What is the shape of the distribution for the data in this study?

What measure of central tendency is most appropriate for describing these data? Why?

On a standard measure of hearing ability, the mean is 300, and the standard deviation is 20. Provide the Z scores for persons whose raw scores are 340, 310, and 260. Provide the raw scores for persons whose Z scores on this test are 2.4, 1.5, and -4.5.

Using the unit normal table, find the proportion under the standard normal curve that lies in the tail for each of the follow useing table starting on page 673 (Hint: Remember to change all percents to decimals):

Z = 1.00

Z = -1.05

Z = 0

Z = 2.80

Z = 1.96

Suppose the scores of architects on a particular creativity test are normally distributed. Using a normal curve table (pp. 673-676 of the text), what percentage of architects have Z scores

above .10?

below .10?

above .20?

below .20?

above 1.10?

below 1.10?

A statistics instructor wants to measure the effectiveness of his teaching skills in a class of 102 students (N = 102). He selects students by waiting at the door to the classroom prior to his lecture and pulling aside every third student to give him or her a questionnaire.

Is this sample design an example of random sampling? Explain.

Assuming that all students attend his class that day, how many students will the instructor select to complete his questionnaire?

Suppose you were going to conduct a survey of visitors to your campus. You want the survey to be as representative as possible.

How would you select the people to survey?

Why would that be your best method?

In a school band, 9 kids play string instruments, 10 kids play woodwind instruments, 7 kids play brass instruments, and 4 kids play percussion instruments.

What is the probability that you randomly select a kid who plays a string or percussion instrument?

What is the probability that you randomly select a kid who does not play a brass instrument?

PSY 315 Week 3 Inferential Research and Statistics Project, Part 1

Resource: Inferential Research and Statistics Project

Use the provided data set to complete Part 1 of the Inferential Research and Statistics Project.

Use Microsoft® Virtual Academy for any help using Microsoft® Excel®.

Select the Assignment Files tab to submit your assignment.

Inferential Research and Statistics Project

Part 1

Select one of the following scenarios based on your particular field of interest in psychology:

Industrial/Organizational Psychology:

o A few months ago, the upper management at a large corporation decided they wanted to make major changes in the organization. Leadership is concerned that employees may be resistant to the change, and they want to find out if there is a change management method that would help employees accept change more effectively and keep employee satisfaction high. Two methods they have considered are the ADKAR Framework and the Prosci Change Management Methodology. The company wants to implement a small change in two departments before they make any major organization changes and would like to test the methods. The corporation uses the Devine Company to measure employee satisfaction with an anonymous survey.

Applied Psychology:

o A large medical facility is experiencing too many missed appointments in its primary and specialty care clinics. The facility has noticed that not all patients respond well to reminder calls regarding follow-up appointments. Some patients do not answer calls and do not seem to respond to voice mail requesting they call the facility. The result is that many follow-up appointments are missed. Facility management have read articles that indicate people respond very well to text messages and would like to see which method provides the least amount of missed appointments. Missed appointments are tracked in the facility database on a monthly basis.

General Psychology:

o Clinicians at a small clinic have been introduced to a new method to treat post-traumatic stress disorder (PTSD) in their clients for veterans. Research indicates that virtual reality (VR) is a highly effective treatment option for patients with PTSD. Currently, the clinic uses only cognitive processing therapy (CPT) with their patients suffering from PTSD. The clinicians would like to find out whether VR therapy has different results from CPT therapy. The measure used by the clinic to measure PTSD symptoms is the Combat Exposure Scale. Both therapies need to be applied for a minimum of 12 weeks to be effective.

Write a 525- to 750-word paper that addresses the following for your chosen scenario:

Clearly define the problem or issue you are addressing. Provide a brief background of any research you have found that might affect your research hypothesis.

Create a research hypothesis based on the information provided in each scenario. You have been given a data set (Microsoft® Excel® document) with two sets of interval data (just the numbers, as you must decide what they represent, such as method A results or method B results). This means you are going to test one thing against another, such as which method works best (step 1 of the steps to hypothesis testing). State the null and research hypotheses. Explain whether these hypotheses require a one-tailed test or two-tailed test, and explain your rationale.

Describe the sample you will use. Sample size will be 30 for each group, which are provided in your data set. Explain what type of sampling you selected.

Do you think you would also collect some descriptive data, such as gender, age, or shift? Why do you think it makes sense to collect descriptive data?

Format your paper according to APA guidelines.

Example

You have a hypothesis that two drugs have different effects on lowering anxiety. You would have anxiety scores for drug A and anxiety scores for drug B (all after 4 weeks of treatment) to run inferential analysis for after 4 weeks.

Null hypothesis is H0: drug A = drug B

Research hypothesis is H1: drug A ≠ drug B

Dependent variable: anxiety score changed after treatment

Independent variable: drug treatment

Because you did not state a direction in your hypotheses (better than or worse than), this will be a two-tailed test. You are looking for differences in either direction. You would set your alpha level of .05 and have a sample for each group of 30 people that were volunteers for the study.

PSY 315 Week 3 Practice Worksheet

Complete the Week 3 Practice Worksheet.

Select the Assignment Files tab to submit your completed worksheet

Week 3 Practice Worksheet

Provide a response to the following prompts.

Note: Each team member should compute the following questions and submit them to the Learning Team forum. The team should then discuss each team member’s answers to ascertain the correct answer for each question. Once your team has answered all the questions, submit a finalized team worksheet.

When a result is not extreme enough to reject the null hypothesis, explain why it is wrong to conclude that your result supports the null hypothesis.

List the five steps of hypothesis testing and explain the procedure and logic of each.

A researcher wants to know whether people who regularly listen to radio talk shows are more or less likely to vote in national elections than people in general.

State the research hypothesis and null hypothesis

Would the researchers use a one- or two-tailed Z test?

The general population (Population 2) has a mean of 30 and a standard deviation of 5, and the cutoff Z score for significance in a study involving one participant is 1.96. If the raw score obtained by the participant is 45, what decisions should be made about the null and research hypotheses?

One hundred people are included in a study in which they are compared to a known population that has a mean of 73, a standard deviation of 20, and a rectangular distribution.

μM = __________.

σM = __________.

The shape of the comparison distribution is __________.

If the sample mean is 75, the lower limit for the 99% confidence interval is __________.

If the sample mean is 75, the upper limit for the 99% confidence interval is __________.

If the sample mean is 75, the lower limit for the 95% confidence interval is __________.

If the sample mean is 75, the upper limit for the 95% confidence interval is __________.

A psychology professor of a large class became curious as to whether the students who turned in tests first scored differently from the overall mean on the test. The overall mean score on the test was 75 with a standard deviation of 10; the scores were approximately normally distributed. The mean score for the first 20 students to turn in tests was 78. Using the .05 significance level, was the average test score earned by the first 20 students to turn in their tests significantly different from the overall mean?

Use the five steps of hypothesis testing.

Figure the confidence limits for the 95% confidence interval.

PSY 315 Week 4 Inferential Research and Statistics Project, Part 2

Resource: Inferential Research and Statistics Project

Complete Part 2 of the Inferential Research and Statistics Project.

Use the provided data set from Week 3.

Select the Assignment Files tab to submit your assignment.

Note: If you have trouble using Microsoft® Excel® to complete this portion of the project, please review the t Test: Two-Sample Assuming Equal Variances Tutorial.

Part 2

Analyze the data from Part 1 using Microsoft® Excel® software.

Write a 700- to 875-word paper that includes the following information:

Describe what method you are using to compare groups.

Copy and paste the output into a Microsoft® Word document, and also answer the following questions:

o What is the significance level of the comparison?

o What was the alpha level you identified in Week 3?

o What was the means and variance for each variable?

o What was the test statistic?

o What was the critical value for both the one- and two-tailed test?

o Was your test one-tailed or two-tailed?

o Were you able to reject the null hypothesis? In other words, did you prove there was a difference?

Talk about what these results mean in everyday language and in context to your chosen scenario.

Make a recommendation based on the findings.

Format your paper according to APA guidelines.

Example of Output You Would Use to Answer These Questions

t Test: Two-Sample Assuming Equal Variances

Variable 1

Variable 2

Mean

4.875

8

Variance

5.267857143

18.28571429

Observations

8

8

Pooled variance

11.77678571

Hypothesized mean difference

0

df

14

t stat

-1.821237697

P(T <= t) one-tail

0.045002328

t Critical one-tail

1.761310136

P(T <= t) two-tail

0.090004655

t Critical two-tail

2.144786688

PSY 315 Week 4 Practice Worksheet

Complete the Week 4 Practice Worksheet.

Use Microsoft® Virtual Academy for any help using Microsoft® Excel®.

Select the Assignment Files tab to submit your assignment.

Week 4 Practice Worksheet

Provide a response to the following prompts.

Note: Each team member should compute the following questions and submit them to the Learning Team forum. The team should then discuss each team member’s answers to ascertain the correct answer for each question. Once your team has answered all the questions, submit a finalized team worksheet.

Two boats, the Prada (Italy) and the Oracle (USA), are competing for a spot in the upcoming America’s Cup race. They race over a part of the course several times. The sample times in minutes for the Prada were as follows: 12.9, 12.5, 11.0, 13.3, 11.2, 11.4, 11.6, 12.3, 14.2, and 11.3. The sample times in minutes for the Oracle were as follows: 14.1, 14.1, 14.2, 17.4, 15.8, 16.7, 16.1, 13.3, 13.4, 13.6, 10.8, and 19.0. For data analysis, the appropriate test is the t test: two-sample assuming unequal variances.

Hypothesis Test: Independent Groups (t test, unequal variance)

Prada

Oracle

12.170

14.875

mean

1.056

2.208

std. dev.

10

12

n

16

df

-2.7050

difference (Prada – Oracle)

0.7196

standard error of difference

0

hypothesized difference

-3.76

t

.0017

p-value (two-tailed)

-4.2304

confidence interval 95% lower

-1.1796

confidence interval 95% upper

1.5254

margin of error

The previous table shows the results of this independent t test. At the .05 significance level, can you conclude that there is a difference in their mean times? Explain these results to a person who knows about the t test for a single sample but who is unfamiliar with the t test for independent means.

The Willow Run Outlet Mall has two Haggar Outlet Stores, one located on Peach Street and the other on Plum Street. The two stores are laid out differently, but both store managers claim their layout maximizes the amounts customers will purchase on impulse. A sample of 10 customers at the Peach Street store revealed they spent the following amounts more than planned: $17.58, $19.73, $12.61, $17.79, $16.22, $15.82, $15.40, $15.86, $11.82, $15.85. A sample of 14 customers at the Plum Street store revealed they spent the following amounts more than they planned when they entered the store: $18.19, $20.22, $17.38, $17.96, $23.92, $15.87, $16.47, $15.96, $16.79, $16.74, $21.40, $20.57, $19.79, $14.83. For data analysis, a t test: two-sample assuming unequal variances was used.

Hypothesis Test: Independent Groups (t test, unequal variance)

Peach Street

Plum Street

15.8680

18.2921

mean

2.3306

2.5527

std. dev.

10

14

n

20

df

-2.42414

difference (Peach Street – Plum Street)

1.00431

standard error of difference

0

hypothesized difference

-2.41

t

.0255

p-value (two-tailed)

-5.28173

confidence interval 99.% lower

0.43345

confidence interval 99.% upper

2.85759

margin of error

At the .01 significance level, is there a difference in the mean amount purchased on an impulse at the two stores? Explain these results to a person who knows about the t test for a single sample but who is unfamiliar with the t test for independent means.

Fry Brothers Heating and Air Conditioning, Inc. employs Larry Clark and George Murnen to make service calls to repair furnaces and air conditioning units in homes. Tom Fry, the owner, would like to know whether there is a difference in the mean number of service calls they make per day. Assume the population standard deviation for Larry Clark is 1.05 calls per day, and 1.23 calls per day for George Murnen. A random sample of 40 days last year showed that Larry Clark made an average of 4.77 calls per day. For a sample of 50 days, George Murnen made an average of 5.02 calls per day.

Hypothesis Test: Independent Groups (t test, pooled variance)

Larry

George

4.77

5.02

mean

1.05

1.23

std. dev.

40

50

n

88

df

-0.25000

difference (Larry – George)

1.33102

pooled variance

1.15370

pooled std. dev.

0.24474

standard error of difference

0

hypothesized difference

-1.02

t

.3098

p-value (two-tailed)

-0.73636

confidence interval 95.% lower

0.23636

confidence interval 95.% upper

0.48636

margin of error

At the .05 significance level, is there a difference in the mean number of calls per day between the two employees? What is the p-value?

An organizational psychologist measures levels of job satisfaction in a sample of 30 participants. To measure the variance of job satisfaction, it is calculated that the SS = 120 for this sample.

What are the degrees of freedom for the variance?

Compute the variance and standard deviation (you will have to do this one by hand).

PSY 315 Week 5 Inferential Research and Statistics Project, Part 3

Resource: Inferential Research and Statistics Project

Complete Part 3 of the Inferential Research and Statistics Project.

Use Tutorials & Guides if you need any help creating your presentation.

Select the Assignment Files tab to submit your assignment.

Create a 12- to 15-slide presentation using the information you gathered and submitted in Weeks 3 and 4. Include the following:

Describe the problem and provide some brief background information about the situation.

Explain the research hypothesis.

Describe your sample and your sampling method.

Explain the four steps of the research process you followed, and define the critical value and the test statistic your analysis provided.

Provide the main finding of the study. What did you prove or fail to prove?

Provide recommendations based on your findings.

Format any citations in your presentation according to APA guidelines.

PSY 315 Week 5 Practice Worksheet

Complete the Week 5 Practice Worksheet.

Use Microsoft® Virtual Academy for any help using Microsoft® Excel®.

Select the Assignment Files tab to submit your completed worksheet.

Week 5 Practice Worksheet

Provide a response to the following prompts.

Note: Each team member should compute the following questions and submit them to the Learning Team forum. The team should then discuss each team member’s answers to ascertain the correct answer for each question. Once your team has answered all the questions, submit a finalized team worksheet.

Your research team has been tasked with finding the correlation of the following scenario:

Four research participants take a test of manual dexterity (high scores mean better dexterity) and an anxiety test (high scores mean more anxiety). The scores are as follows:

Person Dexterity Anxiety

1 1 10

2 1 8

3 2 4

4 4 -2

Describe the process your research team would go through by completing the following:

Create a scatter diagram of the scores.

Describe in words the general pattern of correlation, if any.

Figure the correlation coefficient.

Explain the logic of what you have done, writing as if you are speaking to someone who has never heard of correlation (but who does understand the mean, standard deviation, Z scores, and hypothesis testing).

Provide three logically possible directions of causality, indicating for each direction whether it is a reasonable explanation for the correlation based on the variables involved. Explain your answer.

STATISTICAL REASONING IN PSYCHOLOGY

PSY 315 Week 1 Practice Worksheet

Complete the University of Phoenix Material: Week 1 Practice Worksheet.

Click the Assignment Files tab to submit your assignment.

Week 1 Practice Worksheet

Provide a response to the following questions. Written responses should be at least 30 to 45 words each.

Explain and provide an example for each of the following types of variables:

Nominal:

Ordinal:

Interval:

Ratio scale:

Continuous:

Discrete:

Quantitative:

Qualitative:

The following are the speeds of 40 cars clocked by radar on a particular road in a 35 miles-per-hour zone on an afternoon:

30, 36, 42, 36, 30, 52, 36, 34, 36, 33, 30, 32, 35, 32, 37, 34, 36, 31, 35, 20

24, 46, 23, 31, 32, 45, 34, 37, 28, 40, 34, 38, 40, 52, 31, 33, 15, 27, 36, 40

Create a frequency table and a histogram. Then, describe the general shape of the distribution.

Raskauskas and Stoltz (2007) asked a group of 84 adolescents about their involvement in traditional and electronic bullying. The researchers defined electronic bullying as “…a means of bullying in which peers use electronics (such as text messages, emails, and defaming Web sites) to taunt, threaten, harass, and/or intimidate a peer” (p. 565). The table below is a frequency table showing the adolescents’ reported incidence of being victims or perpetrators of traditional and electronic bullying.

Using the table below as an example, explain the idea of a frequency table to a person who has never taken a course in statistics.

Explain the general meaning of the pattern of results.

Incidence of Traditional and Electronic Bullying and Victimization (N = 84)

Forms of bullying

N

%

Electronic victims

41

48.8

Text-message victim

27

32.1

Internet victim (websites, chatrooms)

13

15.5

Camera-phone victim

8

9.5

Traditional victims

60

71.4

Physical victim

38

45.2

Teasing victim

50

59.5

Rumors victim

32

38.6

Exclusion victim

30

50

Electronic bullies

18

21.4

Text-message bully

18

21.4

Internet bully

11

13.1

Traditional bullies

54

64.3

Physical bully

29

34.5

Teasing bully

38

45.2

Rumor bully

22

26.2

Exclusion bully

35

41.7

Describe whether each of the following data words best describes descriptive statistics or inferential statistics. Explain your reasoning.

Describe:

Infer:

Summarize:

Compare the three types of research methods and statistics.

Regarding gun ownership in the United States, data from Gallup polls over a 40-year period show how gun ownership in the United States has changed. The results are described below, with the percentage of Americans who own guns given in each of the 5 decades.

Year

%

1972

43

1982

42

1992

48

2002

40

2012

43

Are the percentages reported above an example of descriptive statistics or inferential statistics? Why?

Based on the table, how would you describe the changes in gun ownership in the United States over the 40 years shown?

Refer to the Simpson-Southward et al. (2016) article from this week’s electronic readings. Was this an example of inferential statistics and research or descriptive statistics and research? Justify your response.

PSY 315 Week 2 Practice Worksheet

Complete the Week 2 Practice Worksheet.

Use Microsoft® Virtual Academy for any help using Microsoft® Excel®.

Select the Assignment Files tab to submit your completed worksheet.

Week 2 Practice Worksheet

Provide a response to the following prompts.

The Wilcox & Keselman (2003) article from this week’s electronic readings discusses two problems with measures of central tendency: skewness of the data and outliers. Discuss each of these issues and how they affect measures of central tendency.

How do the sample mean and the population mean differ? What is the symbol for each type of mean?

An expert reviews a sample of 10 scientific articles (n = 10) and records the following numbers of error in each article: 0, 4, 2, 8, 2, 3, 1, 0, 5, and 7.

Compute the mean, median, mode, sum of squares (SS), the variance, and the standard deviation for this sample using the definitional and computational formulas. You may use Microsoft® Excel® data anlysis to compute these statistics and copy your output into this worksheet.

Explain, to a person who has never had a course in statistics what you have done.

Note the ways in which the means and standard deviations differ, and speculate on the possible meaning of these differences, presuming they are representative of U.S. governors and large corporations’ CEOs in general.

A researcher records the levels of attraction for various fashion models among college students. He finds that mean levels of attraction are much higher than the median and the mode for these data.

What is the shape of the distribution for the data in this study?

What measure of central tendency is most appropriate for describing these data? Why?

On a standard measure of hearing ability, the mean is 300, and the standard deviation is 20. Provide the Z scores for persons whose raw scores are 340, 310, and 260. Provide the raw scores for persons whose Z scores on this test are 2.4, 1.5, and -4.5.

Using the unit normal table, find the proportion under the standard normal curve that lies in the tail for each of the follow useing table starting on page 673 (Hint: Remember to change all percents to decimals):

Z = 1.00

Z = -1.05

Z = 0

Z = 2.80

Z = 1.96

Suppose the scores of architects on a particular creativity test are normally distributed. Using a normal curve table (pp. 673-676 of the text), what percentage of architects have Z scores

above .10?

below .10?

above .20?

below .20?

above 1.10?

below 1.10?

A statistics instructor wants to measure the effectiveness of his teaching skills in a class of 102 students (N = 102). He selects students by waiting at the door to the classroom prior to his lecture and pulling aside every third student to give him or her a questionnaire.

Is this sample design an example of random sampling? Explain.

Assuming that all students attend his class that day, how many students will the instructor select to complete his questionnaire?

Suppose you were going to conduct a survey of visitors to your campus. You want the survey to be as representative as possible.

How would you select the people to survey?

Why would that be your best method?

In a school band, 9 kids play string instruments, 10 kids play woodwind instruments, 7 kids play brass instruments, and 4 kids play percussion instruments.

What is the probability that you randomly select a kid who plays a string or percussion instrument?

What is the probability that you randomly select a kid who does not play a brass instrument?

PSY 315 Week 3 Inferential Research and Statistics Project, Part 1

Resource: Inferential Research and Statistics Project

Use the provided data set to complete Part 1 of the Inferential Research and Statistics Project.

Use Microsoft® Virtual Academy for any help using Microsoft® Excel®.

Select the Assignment Files tab to submit your assignment.

Inferential Research and Statistics Project

Part 1

Select one of the following scenarios based on your particular field of interest in psychology:

Industrial/Organizational Psychology:

o A few months ago, the upper management at a large corporation decided they wanted to make major changes in the organization. Leadership is concerned that employees may be resistant to the change, and they want to find out if there is a change management method that would help employees accept change more effectively and keep employee satisfaction high. Two methods they have considered are the ADKAR Framework and the Prosci Change Management Methodology. The company wants to implement a small change in two departments before they make any major organization changes and would like to test the methods. The corporation uses the Devine Company to measure employee satisfaction with an anonymous survey.

Applied Psychology:

o A large medical facility is experiencing too many missed appointments in its primary and specialty care clinics. The facility has noticed that not all patients respond well to reminder calls regarding follow-up appointments. Some patients do not answer calls and do not seem to respond to voice mail requesting they call the facility. The result is that many follow-up appointments are missed. Facility management have read articles that indicate people respond very well to text messages and would like to see which method provides the least amount of missed appointments. Missed appointments are tracked in the facility database on a monthly basis.

General Psychology:

o Clinicians at a small clinic have been introduced to a new method to treat post-traumatic stress disorder (PTSD) in their clients for veterans. Research indicates that virtual reality (VR) is a highly effective treatment option for patients with PTSD. Currently, the clinic uses only cognitive processing therapy (CPT) with their patients suffering from PTSD. The clinicians would like to find out whether VR therapy has different results from CPT therapy. The measure used by the clinic to measure PTSD symptoms is the Combat Exposure Scale. Both therapies need to be applied for a minimum of 12 weeks to be effective.

Write a 525- to 750-word paper that addresses the following for your chosen scenario:

Clearly define the problem or issue you are addressing. Provide a brief background of any research you have found that might affect your research hypothesis.

Create a research hypothesis based on the information provided in each scenario. You have been given a data set (Microsoft® Excel® document) with two sets of interval data (just the numbers, as you must decide what they represent, such as method A results or method B results). This means you are going to test one thing against another, such as which method works best (step 1 of the steps to hypothesis testing). State the null and research hypotheses. Explain whether these hypotheses require a one-tailed test or two-tailed test, and explain your rationale.

Describe the sample you will use. Sample size will be 30 for each group, which are provided in your data set. Explain what type of sampling you selected.

Do you think you would also collect some descriptive data, such as gender, age, or shift? Why do you think it makes sense to collect descriptive data?

Format your paper according to APA guidelines.

Example

You have a hypothesis that two drugs have different effects on lowering anxiety. You would have anxiety scores for drug A and anxiety scores for drug B (all after 4 weeks of treatment) to run inferential analysis for after 4 weeks.

Null hypothesis is H0: drug A = drug B

Research hypothesis is H1: drug A ≠ drug B

Dependent variable: anxiety score changed after treatment

Independent variable: drug treatment

Because you did not state a direction in your hypotheses (better than or worse than), this will be a two-tailed test. You are looking for differences in either direction. You would set your alpha level of .05 and have a sample for each group of 30 people that were volunteers for the study.

PSY 315 Week 3 Practice Worksheet

Complete the Week 3 Practice Worksheet.

Select the Assignment Files tab to submit your completed worksheet

Week 3 Practice Worksheet

Provide a response to the following prompts.

Note: Each team member should compute the following questions and submit them to the Learning Team forum. The team should then discuss each team member’s answers to ascertain the correct answer for each question. Once your team has answered all the questions, submit a finalized team worksheet.

When a result is not extreme enough to reject the null hypothesis, explain why it is wrong to conclude that your result supports the null hypothesis.

List the five steps of hypothesis testing and explain the procedure and logic of each.

A researcher wants to know whether people who regularly listen to radio talk shows are more or less likely to vote in national elections than people in general.

State the research hypothesis and null hypothesis

Would the researchers use a one- or two-tailed Z test?

The general population (Population 2) has a mean of 30 and a standard deviation of 5, and the cutoff Z score for significance in a study involving one participant is 1.96. If the raw score obtained by the participant is 45, what decisions should be made about the null and research hypotheses?

One hundred people are included in a study in which they are compared to a known population that has a mean of 73, a standard deviation of 20, and a rectangular distribution.

μM = __________.

σM = __________.

The shape of the comparison distribution is __________.

If the sample mean is 75, the lower limit for the 99% confidence interval is __________.

If the sample mean is 75, the upper limit for the 99% confidence interval is __________.

If the sample mean is 75, the lower limit for the 95% confidence interval is __________.

If the sample mean is 75, the upper limit for the 95% confidence interval is __________.

A psychology professor of a large class became curious as to whether the students who turned in tests first scored differently from the overall mean on the test. The overall mean score on the test was 75 with a standard deviation of 10; the scores were approximately normally distributed. The mean score for the first 20 students to turn in tests was 78. Using the .05 significance level, was the average test score earned by the first 20 students to turn in their tests significantly different from the overall mean?

Use the five steps of hypothesis testing.

Figure the confidence limits for the 95% confidence interval.

PSY 315 Week 4 Inferential Research and Statistics Project, Part 2

Resource: Inferential Research and Statistics Project

Complete Part 2 of the Inferential Research and Statistics Project.

Use the provided data set from Week 3.

Select the Assignment Files tab to submit your assignment.

Note: If you have trouble using Microsoft® Excel® to complete this portion of the project, please review the t Test: Two-Sample Assuming Equal Variances Tutorial.

Part 2

Analyze the data from Part 1 using Microsoft® Excel® software.

Write a 700- to 875-word paper that includes the following information:

Describe what method you are using to compare groups.

Copy and paste the output into a Microsoft® Word document, and also answer the following questions:

o What is the significance level of the comparison?

o What was the alpha level you identified in Week 3?

o What was the means and variance for each variable?

o What was the test statistic?

o What was the critical value for both the one- and two-tailed test?

o Was your test one-tailed or two-tailed?

o Were you able to reject the null hypothesis? In other words, did you prove there was a difference?

Talk about what these results mean in everyday language and in context to your chosen scenario.

Make a recommendation based on the findings.

Format your paper according to APA guidelines.

Example of Output You Would Use to Answer These Questions

t Test: Two-Sample Assuming Equal Variances

Variable 1

Variable 2

Mean

4.875

8

Variance

5.267857143

18.28571429

Observations

8

8

Pooled variance

11.77678571

Hypothesized mean difference

0

df

14

t stat

-1.821237697

P(T <= t) one-tail

0.045002328

t Critical one-tail

1.761310136

P(T <= t) two-tail

0.090004655

t Critical two-tail

2.144786688

PSY 315 Week 4 Practice Worksheet

Complete the Week 4 Practice Worksheet.

Use Microsoft® Virtual Academy for any help using Microsoft® Excel®.

Select the Assignment Files tab to submit your assignment.

Week 4 Practice Worksheet

Provide a response to the following prompts.

Note: Each team member should compute the following questions and submit them to the Learning Team forum. The team should then discuss each team member’s answers to ascertain the correct answer for each question. Once your team has answered all the questions, submit a finalized team worksheet.

Two boats, the Prada (Italy) and the Oracle (USA), are competing for a spot in the upcoming America’s Cup race. They race over a part of the course several times. The sample times in minutes for the Prada were as follows: 12.9, 12.5, 11.0, 13.3, 11.2, 11.4, 11.6, 12.3, 14.2, and 11.3. The sample times in minutes for the Oracle were as follows: 14.1, 14.1, 14.2, 17.4, 15.8, 16.7, 16.1, 13.3, 13.4, 13.6, 10.8, and 19.0. For data analysis, the appropriate test is the t test: two-sample assuming unequal variances.

Hypothesis Test: Independent Groups (t test, unequal variance)

Prada

Oracle

12.170

14.875

mean

1.056

2.208

std. dev.

10

12

n

16

df

-2.7050

difference (Prada – Oracle)

0.7196

standard error of difference

0

hypothesized difference

-3.76

t

.0017

p-value (two-tailed)

-4.2304

confidence interval 95% lower

-1.1796

confidence interval 95% upper

1.5254

margin of error

The previous table shows the results of this independent t test. At the .05 significance level, can you conclude that there is a difference in their mean times? Explain these results to a person who knows about the t test for a single sample but who is unfamiliar with the t test for independent means.

The Willow Run Outlet Mall has two Haggar Outlet Stores, one located on Peach Street and the other on Plum Street. The two stores are laid out differently, but both store managers claim their layout maximizes the amounts customers will purchase on impulse. A sample of 10 customers at the Peach Street store revealed they spent the following amounts more than planned: $17.58, $19.73, $12.61, $17.79, $16.22, $15.82, $15.40, $15.86, $11.82, $15.85. A sample of 14 customers at the Plum Street store revealed they spent the following amounts more than they planned when they entered the store: $18.19, $20.22, $17.38, $17.96, $23.92, $15.87, $16.47, $15.96, $16.79, $16.74, $21.40, $20.57, $19.79, $14.83. For data analysis, a t test: two-sample assuming unequal variances was used.

Hypothesis Test: Independent Groups (t test, unequal variance)

Peach Street

Plum Street

15.8680

18.2921

mean

2.3306

2.5527

std. dev.

10

14

n

20

df

-2.42414

difference (Peach Street – Plum Street)

1.00431

standard error of difference

0

hypothesized difference

-2.41

t

.0255

p-value (two-tailed)

-5.28173

confidence interval 99.% lower

0.43345

confidence interval 99.% upper

2.85759

margin of error

At the .01 significance level, is there a difference in the mean amount purchased on an impulse at the two stores? Explain these results to a person who knows about the t test for a single sample but who is unfamiliar with the t test for independent means.

Fry Brothers Heating and Air Conditioning, Inc. employs Larry Clark and George Murnen to make service calls to repair furnaces and air conditioning units in homes. Tom Fry, the owner, would like to know whether there is a difference in the mean number of service calls they make per day. Assume the population standard deviation for Larry Clark is 1.05 calls per day, and 1.23 calls per day for George Murnen. A random sample of 40 days last year showed that Larry Clark made an average of 4.77 calls per day. For a sample of 50 days, George Murnen made an average of 5.02 calls per day.

Hypothesis Test: Independent Groups (t test, pooled variance)

Larry

George

4.77

5.02

mean

1.05

1.23

std. dev.

40

50

n

88

df

-0.25000

difference (Larry – George)

1.33102

pooled variance

1.15370

pooled std. dev.

0.24474

standard error of difference

0

hypothesized difference

-1.02

t

.3098

p-value (two-tailed)

-0.73636

confidence interval 95.% lower

0.23636

confidence interval 95.% upper

0.48636

margin of error

At the .05 significance level, is there a difference in the mean number of calls per day between the two employees? What is the p-value?

An organizational psychologist measures levels of job satisfaction in a sample of 30 participants. To measure the variance of job satisfaction, it is calculated that the SS = 120 for this sample.

What are the degrees of freedom for the variance?

Compute the variance and standard deviation (you will have to do this one by hand).

PSY 315 Week 5 Inferential Research and Statistics Project, Part 3

Resource: Inferential Research and Statistics Project

Complete Part 3 of the Inferential Research and Statistics Project.

Use Tutorials & Guides if you need any help creating your presentation.

Select the Assignment Files tab to submit your assignment.

Create a 12- to 15-slide presentation using the information you gathered and submitted in Weeks 3 and 4. Include the following:

Describe the problem and provide some brief background information about the situation.

Explain the research hypothesis.

Describe your sample and your sampling method.

Explain the four steps of the research process you followed, and define the critical value and the test statistic your analysis provided.

Provide the main finding of the study. What did you prove or fail to prove?

Provide recommendations based on your findings.

Format any citations in your presentation according to APA guidelines.

PSY 315 Week 5 Practice Worksheet

Complete the Week 5 Practice Worksheet.

Use Microsoft® Virtual Academy for any help using Microsoft® Excel®.

Select the Assignment Files tab to submit your completed worksheet.

Week 5 Practice Worksheet

Provide a response to the following prompts.

Note: Each team member should compute the following questions and submit them to the Learning Team forum. The team should then discuss each team member’s answers to ascertain the correct answer for each question. Once your team has answered all the questions, submit a finalized team worksheet.

Your research team has been tasked with finding the correlation of the following scenario:

Four research participants take a test of manual dexterity (high scores mean better dexterity) and an anxiety test (high scores mean more anxiety). The scores are as follows:

Person Dexterity Anxiety

1 1 10

2 1 8

3 2 4

4 4 -2

Describe the process your research team would go through by completing the following:

Create a scatter diagram of the scores.

Describe in words the general pattern of correlation, if any.

Figure the correlation coefficient.

Explain the logic of what you have done, writing as if you are speaking to someone who has never heard of correlation (but who does understand the mean, standard deviation, Z scores, and hypothesis testing).

Provide three logically possible directions of causality, indicating for each direction whether it is a reasonable explanation for the correlation based on the variables involved. Explain your answer.

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