Take Home Midterm Exam

RSCH 6110 / 8110

Use Excel and SPSS as we have during class to complete this exam. Most of these questions involve things you have already calculated in class exercises. Therefore, it may be useful to cut and paste from your previous assignments as needed. You may work in your groups on this exam. Each individual must turn their own exam.

1.(10 points) Based on the real world data you have brought to class, develop a problem statement for a research project you would like to conduct. Select a problem that is related to your field of study or work. The focus of this exam is correlation and regression. Therefore, select a problem that can be addressed with such methods. Include in the statement the following:

  1. The population to be studied.
  2. The sampling strategies used to create your dataset.
  3. The context or setting within which the subjects will be studied and data collected
  4. Identify one variable as the Independent Variable and one as the Dependent Variable.
  5. The hypothesized relationship between the two variables that you wish to investigate.
  6. The theoretical or practical importance of the research.

2. (10 points) Calculate the following descriptive statistics on both the independent and dependent variables:

a. Mean, Median, and Mode

b. Standard Deviation

c. Minimum, Maximum, 25th, and 75th percentiles.

3. (10 points) Create histograms and boxplots for the independent and dependent variables.

Interpret these graphs and report what they tell you about the distributions of the independent and dependent variables. Discuss outliers as needed.

4. (10 points) Based on your answers to #2 and #3, describe the characteristics of your sample on the independent and dependent variables. Comment on what the descriptive statistics tell you about the potential generalizability of the results from your study. Comment on how representative your data is of the population of interest.

5. (10 points) Compute the correlation coefficient and coefficients of determination and non-determination for the relationship between the variables.

6. (10 points) Compute the components of the regression line. Write out the equation for the regression line.

7. (10 points) Using the residuals and predicted values saved by SPSS, compute the coefficients of determination and non-determination. Explain how you used the residual information to make these calculations.

8. (10 points) Produce the scatterplot that depicts the relationship between your independent and dependent variables using SPSS or Excel. Plot the regression line for the relationship between the variables on the scatterplot.

9. (10 points) Interpret the residual plot from SPSS. Interpret the standard error of estimate. Select a few (3-4) specific cases to discuss. Using a contingency table created in Excel, simulate what the regression equation would predict for the specific cases of interest.

10. (10 points) Interpret the findings of your study. Comment on the nature of the relationship between the variables and any relevant implications for theory or practice. Make a judgment about whether the data fit the model, or equation.