Part I: General Concepts

These questions are based on the concepts covered in this module’s assigned readings and presentations.

You find a partial report of a study that investigated the relationship between self-esteem and depression. You see they conducted a one-tailed Pearon’s r correlation with 52 people, and that the r = -0.25. Answer the following questions based on this result.

1.

Calculate / report the following:

a. Coefficient of determination

b. degrees of freedom

c. critical r value (use the ebook appendix for the critical value and do not round).

(make sure to keep labels a, b, and c!)

a. ANSWER

b. ANSWER

c. ANSWER

2.

Write up the results using complete sentences. Make sure to include the full statistical notation and a decision about the null hypothesis.

ANSWER

3.

State what a researcher would conclude and what is actually true if a Type I error were committed in this scenario. (Note this requires two statements – 1) what the researcher concludes and 2) what is true for the population.)

ANSWER

4.

Imagine a study finds a significant positive relationship between IQ and SAT scores. If a journalist made an error in causality when writing about this relationship, what would they be claiming / concluding based on this scenario (one sentence is sufficient)?

ANSWER

5.

State what a researcher would conclude and what is actually true if a Type II error were committed in regards to a correlational study on IQ and SAT scores. (Note this requires two statements – 1) what the researcher concludes and 2) what is true for the population.)

ANSWER

Scenario: A professor wants to examine whether being an athlete is associated with retention at their college. She finds that the research is contradictory – some research suggests it may improve retention but other research suggests it has no effect. She operationally defines athletic status as YES or NO, and retention as a self-report question (scale of 0 – 100% likelihood of coming back the next term).

6.

What is the null hypothesis in this scenario (use a complete sentence)? Is it one- or two-tailed?

ANSWER

7.

What type of correlational analysis is most appropriate and why?

ANSWER

Part II: SPSS Application

These questions require the use of SPSS. Remember you must submit all of your work within this word document. You will need to take a screen shot of your data view if necessary, or copy and paste your output into the spaces below. Remember to report the exact p value provided by SPSS output – simply reporting p<.05 or p>.05 is not acceptable (unless SPSS output states p=.000 – in that case you can report p<.001).

A researcher wants to examine what impacts GPA. In addition to GPA, she measures perceptions of the teacher, perception of class content, motivation, IQ, hours studied, and final grade. Teacher perception was assessed using a ranking scale of low positive, moderate positive, or high positive teacher perception. Perception of the class was self reported as either “YES” or “NO” with the question of “Do you believe this course will help prepare you for a meaningful career?” Motivation is assessed using a standardized scale that ranges from 0 – 100, which higher scores indicating more motivation. Hours studied is the average amount studied per week, and final grade was the final percent earned in the class. This data set is located in the current module and is titled “ Correlation & Regression SPSS Data Set”.

8.

Conduct a Pearson correlation to determine whether there is a positive relationship between motivation (motscore) and GPA. Paste the relevant SPSS output below.

ANSWER

9.

Write the results in APA style. Make sure to indicate whether it is one or two-tailed and if appropriate, the coefficient of determination.

ANSWER

10.

Conduct a linear regression to see if you can predict GPA based on hours studied (hrsstudy). Paste the relevant SPSS output below.

ANSWER

11.

Write the results in APA style.

ANSWER

12.

Create an appropriate graph for this data if using a regression equation.

ANSWER

Part III: Cumulative

These questions can be related to anything covered thus far in the course.

13.

Describe a variable that would likely result in a positively skewed distribution. Justify your rationale, using example numbers for the mean, median, and mode.

ANSWER

14.

Describe a variable that would likely result in platykurtic distribution. Justify your rationale making sure to describe the dispersion of scores.

ANSWER

15.

If you are looking at scores on an exam and they seem rather normally distributed except for one extremely low score, what would be the most appropriate measure of central tendency to describe the distribution?

ANSWER

16.

Where would you go within an introduction to find the rationale, problem statement, and hypothesis (near the beginning, middle, or end)? (see M1 Introduction to Research Methods presentation for a refresher!).

ANSWER

17.

Researcher Jane believes she’s developed a new measure for stress. How can she measure its construct validity?

ANSWER

18.

Give an example of a subject / participant variable (review ch. 1).

ANSWER