1. Using the Nebraska Inmate Survey (NIS), choose 1 dichotomous variable that is of interest to you. Create a bar chart. Copy and paste the results below. Interpret the bar chart.
2. Using the Nebraska Inmate Survey (NIS), choose 1 variable that is ordinal, interval, or ratio and is of interest to you. Create a pie chart. Copy and paste the results below. Interpret the pie chart.
3. Using the Nebraska Inmate Survey (NIS), choose 1 NEW variable that is ordinal, interval, or ratio and is of interest to you. Create a histogram. Be sure to display the normal distribution. Copy and paste the results below. Interpret the histogram. Is your variable normally distributed?
4. Using your own words, explain what it means if two variables are correlated. Next, using the Nebraska Inmate Survey (NIS), choose 2 NEW variables that are both ordinal, interval, or ratio and of interest to you. You will need an independent variable and a dependent variable. Indicate below your hypothesis noting which variable is your independent and dependent variable. For example: Those who are more highly educated are less likely to have been on probation. Independent variable: Education; Dependent variable: Probation. Make sure your temporal order is logical.
5. Using your own words, describe why scatterplots are useful. Create a scatterplot using your variables from number 4. Copy and paste the results below. Interpret the scatterplot. Do the variables appear to be correlated?
6. What is a Pearson correlation coefficient and what does it tell us (using your own words)? How is it different from the Spearman correlation coefficient? Using the same variables from number 4, run a Pearson correlation coefficient and a Spearman correlation coefficient. Copy and paste your results below. Indicate if your findings are significant or non-significant and interpret your results accordingly (see Cronk p. 46-49). An acceptable significance level is p < .05. Be sure you indicate the strength of the correlations, as well as the direction.
SPSS Lab #4:
Comparing Means: T-Tests & ANOVA
Please use this word document to complete the lab. Please keep all instructions/questions in this document. Answer each question within the document.
1. Using the Nebraska Inmate Survey (NIS), run an independent-samples t-test. Choose 1 dichotomous variable (which will serve as your independent or grouping variable) and choose 1 interval or ratio variable (which will serve as your dependent variable). Copy and paste your output below. Using the equal variances assumed row in the output, interpret your findings. Note if the findings are significant or not, and what that means. See pages 64-65 (Cronk) for help interpreting your t-test.
2. Using the Nebraska Inmate Survey (NIS), run a single-sample t-test. Choose 1 interval or ratio variable (which will serve as your dependent variable). You will have to find the mean of the variable you chose from the population. Thus, this will require some outside research. Below, indicate the mean of the variable from the population. Then, run your t-test and indicate the mean of the variable from the sample. Copy and paste your output below. Interpret your findings. Note if the findings are significant or not, and what that means. See pages 61-62 (Cronk) for help interpreting your t-test.
3. Why would you use a paired sample t-test? Provide a hypothetical criminal justice example of when a paired sample t-test would be used.
4. Using the Nebraska Inmate Survey (NIS), run a One-Way ANOVA. Your independent variable is the grouping that you are interested in. Groups should be independent of each other (e.g., married, divorced, widowed). You cannot use my example. Then, choose a dependent variable that is interval or ratio. Run a One-Way ANOVA in SPSS. Copy and paste your output below. Interpret your findings. See pages 71-31 (Cronk) for help interpreting your ANOVA.
