## PSYCH 625 Weekly Individual Assignment Papers

PSYCH 625 Weekly Individual Assignment Papers

### PSYCH 625 Week 1 Individual Assignment Basic Concepts in Statistics Worksheet

**Complete** the following questions. Be specific and provide examples when relevant.

**Cite** any sources consistent with APA guidelines.

What are statistics and how are they used in the behavioral sciences? Your answer should be 100 to 200 words.

Differentiate between descriptive and inferential statistics. What information do they provide? What are their similarities and differences? Your answer should be 250 to 400 words.

What is a population? What is a sample? How are they similar and how are they different? When would you use one or the other? Your answer should be 250 to 400 words.

Go to the library and find a journal article in your area of interest that contains empirical data, but does not contain any visual representation of the data. Use the data to create a chart. Specify what type of chart you are creating, and why you chose the one you did. You can create the chart manually or using IBM^{®} SPSS^{®} software or a Microsoft^{®} Excel^{®} document. The chart may be pasted into this document or submitted as an attachment with this document. Hypotheses and Analysis Assignment Papers

#### PSYCH 625 Weekly Individual Assignment Papers – Week 2 Individual Assignment Time to Practice – Week Two

**Complete** Parts A, B, and C below.

Part A

Some questions in Part A require that you access data from *Statistics for People Who (Think They) Hate Statistics. *This data is available on the student website under the Student Text Resources link.

1. Why is a *z* score a standard score? Why can standard scores be used to compare scores from different distributions

2.For the following set of scores, fill in the cells. The mean is 70 and the standard deviation is 8

3. Questions 3a through 3d are based on a distribution of scores with and the standard deviation = 6.38. Draw a small picture to help you see what is required

4. Jake needs to score in the top 10% in order to earn a physical fitness certificate. The class mean is 78 and the standard deviation is 5.5. What raw score does he need

5. Who is the better student, relative to his or her classmates? Use the following table for information

Part B

Some questions in Part B require that you access data from Using SPSS for Windows and Macintosh. This data is available on the student website under the Student Text Resources link.

The data for Exercises 6 and 7 are in the data file named Lesson 20 Exercise File 1. Answer Exercises 6 and 7 based on the following research problem:

Ann wants to describe the demographic characteristics of a sample of 25 individuals who completed a large-scale survey. She has demographic data on the participants’ gender (two categories), educational level (four categories), marital status (three categories), and community population size (eight categories).

6. Using IBM® SPSS® software, conduct a frequency analysis on the gender and marital status variables. From the output, identify the following

7. Using IBM® SPSS® software, create a frequency table to summarize the data on the educational level variable

8. David collects anxiety scores from 15 college students who visit the university health center during finals week. Compute descriptive statistics on the anxiety scores. From the output, identify the following

Part C

**Complete** the questions below. Be specific and provide examples when relevant.

**Cite** any sources consistent with APA guidelines

What is the relationship between reliability and validity?

How can a test be reliable but not valid?

Can a test be valid but not reliable?

Why or why not?

How does understanding probability help you understand statistics

How could you use standard scores and the standard distribution to compare the reading scores of two students receiving special reading resource help and one student in a standard classroom who does not get special help

In a standard normal distribution: What does a *z* score of 1 represent?

What percent of cases fall between the mean and one standard deviation above the mean?

What percent fall between the mean and –1 to +1 standard deviations from the mean?

What percent of scores will fall between –3 and +3 standard deviations under the normal curve.

### PSYCH 625 Weekly Individual Assignment Papers – Week 4 Individual Assignment Time to Practice – Week Four

**Complete** Parts A, B, and C below.

Part A

Some questions in Part A require that you access data from *Statistics for People Who (Think They) Hate Statistics. *This data is available on the student website under the Student Text Resources link.

1. Using the data in the file named Ch. 11 Data Set 2, test the research hypothesis at the .05 level of significance that boys raise their hands in class more often than girls. Do this practice problem by hand using a calculator. What is your conclusion regarding the research hypothesis? Remember to first decide whether this is a one- or two-tailed test

2. Using the same data set (Ch. 11 Data Set 2), test the research hypothesis at the .01 level of significance that there is a difference between boys and girls in the number of times they raise their hands in class. Do this practice problem by hand using a calculator. What is your conclusion regarding the research hypothesis? You used the same data for this problem as for Question 1, but you have a different hypothesis (one is directional and the other is nondirectional). How do the results differ and why

3. Practice the following problems by hand just to see if you can get the numbers right. Using the following information, calculate the *t* test statistic

4. Using the results you got from Question 3 and a level of significance at .05, what are the two-tailed critical values associated with each? Would the null hypothesis be rejected

5. Using the data in the file named Ch. 11 Data Set 3, test the null hypothesis that urban and rural residents both have the same attitude toward gun control. Use IBM® SPSS® software to complete the analysis for this problem

6. A public health researcher tested the hypothesis that providing new car buyers with child safety seats will also act as an incentive for parents to take other measures to protect their children (such as driving more safely, child-proofing the home, and so on). Dr. L counted all the occurrences of safe behaviors in the cars and homes of the parents who accepted the seats versus those who did not. The findings: a significant difference at the .013 level. Another researcher did exactly the same study; everything was the same—same type of sample, same outcome measures, same car seats, and so on. Dr. R’s results were marginally significant (recall Ch. 9) at the .051 level. Which result do you trust more and why

7. In the following examples, indicate whether you would perform a *t*test of independent means or dependent means

Two groups were exposed to different treatment levels for ankle sprains. Which treatment was most effective

A researcher in nursing wanted to know if the recovery of patients was quicker when some received additional in-home care whereas when others received the standard amount

A group of adolescent boys was offered interpersonal skills counseling and then tested in September and May to see if there was any impact on family harmony

One group of adult men was given instructions in reducing their high blood pressure whereas another was not given any instructions

One group of men was provided access to an exercise program and tested two times over a 6-month period for heart health

8. For Ch. 12 Data Set 3, compute the *t* value and write a conclusion on whether there is a difference in satisfaction level in a group of families’ use of service centers following a social service intervention on a scale from 1 to 15. Do this exercise using IBM® SPSS® software, and report the exact probability of the outcome

9. Do this exercise by hand. A famous brand-name manufacturer wants to know whether people prefer Nibbles or Wribbles. They sample each type of cracker and indicate their like or dislike on a scale from 1 to 10. Which do they like the most

10. Using the following table, provide three examples of a simple one-way ANOVA, two examples of a two-factor ANOVA, and one example of a three-factor ANOVA. Complete the table for the missing examples. Identify the grouping and the test variable

11. Using the data in Ch. 13 Data Set 2 and the IBM® SPSS® software, compute the *F* ratio for a comparison between the three levels representing the average amount of time that swimmers practice weekly (< 15, 15–25, and > 25 hours) with the outcome variable being their time for the 100-yard freestyle. Does practice time make a difference? Use the Options feature to obtain the means for the groups

12. When would you use a factorial ANOVA rather than a simple ANOVA to test the significance of the difference between the averages of two or more groups

13. Create a drawing or plan for a 2 × 3 experimental design that would lend itself to a factorial ANOVA. Identify the independent and dependent variables

Part B

Some questions in Part B require that you access data from Using SPSS for Windows and Macintosh. This data is available on the student website under the Student Text Resources link.

The data for Exercise 14 is in the data file named Lesson 22 Exercise File 1.

14. John is interested in determining if a new teaching method, the involvement technique, is effective in teaching algebra to first graders. John randomly samples six first graders from all first graders within the Lawrence City School System and individually teaches them algebra with the new method. Next, the pupils complete an eight-item algebra test. Each item describes a problem and presents four possible answers to the problem. The scores on each item are 1 or 0, where 1 indicates a correct response and 0 indicates a wrong response. The IBM® SPSS® data file contains six cases, each with eight item scores for the algebra test.

Conduct a one-sample *t* test on the total scores. On the output, identify the following

15. Marvin is interested in whether blonds, brunets, and redheads differ with respect to their extrovertedness. He randomly samples 18 men from his local college campus: six blonds, six brunets, and six redheads. He then administers a measure of social extroversion to each individual.

Conduct a one-way ANOVA to investigate the relationship between hair color and social extroversion. Conduct appropriate post hoc tests. On the output, identify the following

Part C

**Complete** the questions below. Be specific and provide examples when relevant.

Cite any sources consistent with guidelines

What is meant by independent samples? Provide a research example of two independent samples

When is it appropriate to use a *t* test for dependent samples? What is the key piece of information you must know in order to decide

When is it appropriate to use an ANOVA? What is the key piece of information you must know in order to decide

Why would you want to do an ANOVA when you have more than two groups, rather than just comparing each pair of means with a *t* test. Hypotheses and Analysis Assignment Papers

#### PSYCH 625 Weekly Individual Assignment Papers – Week 5 Individual Assignment Programmatic Assessment Time to Practice – Week Five

**Complete** Parts A, B, and C below.

Part A

Some questions in Part A require that you access data from *Statistics for People Who (Think They) Hate Statistics. *This data is available on the student website under the Student Text Resources link.

1. Use the following data to answer Questions 1a and 1b

Compute the Pearson product-moment correlation coefficient by hand and show all your work

Construct a scatterplot for these 10 values by hand. Based on the scatterplot, would you predict the correlation to be direct or indirect? Why

2. Rank the following correlation coefficients on strength of their relationship (list the weakest first)

3. Use IBM® SPSS® software to determine the correlation between hours of studying and grade point average for these honor students. Why is the correlation so low

4. Look at the following table.

What type of correlation coefficient would you use to examine the relationship between ethnicity (defined as different categories) and political affiliation

5. When two variables are correlated (such as strength and running speed), it also means that they are associated with one another. But if they are associated with one another, then why does one not cause the other

6. Given the following information, use Table B.4 in Appendix B of *Statistics for People Who (Think They) Hate Statistics* to determine whether the correlations are significant and how you would interpret the results

The correlation between speed and strength for 20 women is .567. Test these results at the .01 level using a one-tailed test

The correlation between the number correct on a math test and the time it takes to complete the test is –.45. Test whether this correlation is significant for 80 children at the .05 level of significance. Choose either a one- or a two-tailed test and justify your choice

The correlation between number of friends and grade point average (GPA) for 50 adolescents is .37. Is this significant at the .05 level for a two-tailed test

7. Use the data in Ch. 15 Data Set 3 to answer the questions below. Do this one manually or use IBM® SPSS® software

Compute the correlation between income and level of education

Test for the significance of the correlation

What argument can you make to support the conclusion that lower levels of education cause low income

8. Use the following data set to answer the questions. Do this one manually

Compute the correlation between age in months and number of words known

Test for the significance of the correlation at the .05 level of significance

Recall what you learned in Ch. 5 of Salkind (2011) about correlation coefficients and interpret this correlation

9. How does linear regression differ from analysis of variance

10. Betsy is interested in predicting how many 75-year-olds will develop Alzheimer’s disease and is using level of education and general physical health graded on a scale from 1 to 10 as predictors. But she is interested in using other predictor variables as well. Answer the following questions

What criteria should she use in the selection of other predictors? Why

Name two other predictors that you think might be related to the development of Alzheimer’s disease

With the four predictor variables (level of education, general physical health, and the two new ones that you name), draw out what the model of the regression equation would look like

11. Joe Coach was curious to know if the average number of games won in a year predicts Super Bowl performance (win or lose). The x variable was the average number of games won during the past 10 seasons. The y variable was whether the team ever won the Super Bowl during the past 10 seasons. Refer to the following data set

How would you assess the usefulness of the average number of wins as a predictor of whether a team ever won a Super Bowl. Hypotheses and Analysis Assignment Papers

What’s the advantage of being able to use a categorical variable (such as 1 or 0) as a dependent variable

What other variables might you use to predict the dependent variable, and why would you choose them

Part B

Some questions in Part B require that you access data from Using SPSS for Windows and Macintosh. This data is available on the student website under the Student Text Resources link. The data for this exercise is in the data file named Lesson 33 Exercise File 1.

Peter was interested in determining if children who hit a bobo doll more frequently would display more or less aggressive behavior on the playground. He was given permission to observe 10 boys in a nursery school classroom. Each boy was encouraged to hit a bobo doll for 5 minutes. The number of times each boy struck the bobo doll was recorded (bobo). Next, Peter observed the boys on the playground for an hour and recorded the number of times each boy struck a classmate (peer). Hypotheses and Analysis Assignment Papers

Conduct a linear regression to predict the number of times a boy would strike a classmate from the number of times the boy hit a bobo doll. From the output, identify the following

Slope associated with the predictor

Additive constant for the regression equation

Mean number of times they struck a classmate

Correlation between the number of times they hit the bobo doll and the number of times they struck a classmate

Standard error of estimate. PSYCH 625 Weekly Individual Assignment Papers

Part C

**Complete** the questions below. Be specific and provide examples when relevant.

Cite any sources consistent with APA guidelines

Draw a scatterplot of each of the following:

A strong positive correlation

A strong negative correlation

A weak positive correlation

A weak negative correlation

Give a realistic example of each

What is the coefficient of determination? What is the coefficient of alienation?

Why is it important to know the amount of shared variance when interpreting both the significance and the meaningfulness of a correlation coefficient

If a researcher wanted to predict how well a student might do in college, what variables do you think he or she might examine?

What statistical procedure would he or she use.

What is the meaning of the *p* value of a correlation coefficient. PSYCH 625 Weekly Individual Assignment Papers