Previously in this course, you worked with parametric statistics like t-tests, ANOVAs, and correlations. In order to use parametric procedures such as those, the dependent variable must be measured on either an interval or a ratio scale. Sometime, however, the variables of interest are categorical; that is, they are not measured on an interval or a ratio scale. For example, the categorical variables of gender, race, or political affiliation are not measured with interval or ratio scales. examine the nonparametric procedure called chi square, which allows you to analyze categorical data.
Imagine that you have information about how 20 nursing students and 20 psychology students felt about starting PSYC 3002 on Day 1 of this class. You want to know if nursing students and psychology students felt differently about embarking on the Introduction to Basic Statistics journey.
Data Set:
Nursing Psychology
Nervous 5 8
Excited 15 12
- Recall the four scales of measurement you learned about in Week 1 (i.e., nominal, ordinal, interval, ratio). Explain what scale of measurement is used to measure academic program in this example. How do you know?
- Explain what scale of measurement is used to measure feeling about PSYC 3002. Explain how you know.
- State whether this scenario requires a goodness of fit test or a test of independence. Explain your answer.
- Before computing the chi square, state the null hypothesis and alternative hypothesis in words (not formulas).
- Identify the obtained χ2 using SPSS.
- State the degrees of freedom and explain how you calculated it by hand.
- Identify the p value using SPSS.
- Explain whether you should retain or reject the null hypothesis and why.
- Are the results statistically significant? How do you know?
- Explain what you can determine about the relationship between academic program and feelings about PSYC 3002.