Description
Criminal justice agencies often gather large quantities of variables to be used in descriptive analyses—that is, to help describe situations, populations, and so on. For instance, the Department of Corrections collects data on inmates. Variables often include the following:
Crime type
Race
Gender
Originating jurisdiction (where they were convicted)
Education level
These data are often captured categorically rather than numerically. For instance, education level might be captured by simply identifying the name of the highest educational attainment that an offender learned, such as the following:
High school diploma or General Education Development (GED)
Bachelor’s degree
Associate’s degree
Similarly, race data are most often captured by recording the label of the race the offender belongs to, such as the following:
Caucasian
African-American
Asian
Native American
Pacific Islander
These labels have no inherent numerical value because they are simply categories. Thus, they are categorical variables.
You cannot use traditional statistical analysis to investigate relationships between categorical variables because they are not numbers. Instead, you would use nonparametric tests, such as the chi-square test of independence. You will use this test to investigate the given data in this assignment.
This assignment has two steps.
Step 1: Watch both of the following videos regarding chi-square analysis:
https://www.khanacademy.org/math/statistics-probability/inference-categorical-data-chi-square-tests/chi-square-tests-for-homogeneity-and-association-independence/v/frequency-table-independent-events
https://www.khanacademy.org/math/statistics-probability/inference-categorical-data-chi-square-tests/chi-square-tests-for-homogeneity-and-association-independence/v/contingency-table-chi-square-test
Filling Out Frequency Table for Independent Events
Contingency Table Chi-Square Test
Step 2: Calculate chi-square using the data in the given table, this Chi Square Example Handout, and the Distribution Values Chart that go with this Individual Project.
Then, answer the following questions about your results:
What is the column total for Caucasian?
What is the column total for African-American?
What is the row total for Denver County?
What is the row total for El Paso County?
What is the row total for Pueblo County?
Are race and originating jurisdiction significantly dependent? How do you know?
What is the final chi-square value?
How many degrees of freedom are there for this chi-square table?
What is the value for the 0.05 significance level and 2 degrees of freedom on the Chi-Square Distribution Values Chart?
Do you reject or accept the null hypothesis that states, “Originating jurisdiction and race are not significantly dependent (they are independent)”?
Using the Chi-Square Example Handout and the Chi-Square Distribution Values Chart as guides to figure the calculations, calculate chi-square for the following data:
