A researcher is interested in investigating 3 types of interventions designed to increase physical activity.The independent variable is the type of intervention and the dependent variable is amount of physical activity,measured in minutes per week.If this researcher wanted to use chi-square to analyze the data,what modification would need to be made?
A)Formulas utilizing degrees of freedom need to be modified to N-3.
B)Subtract .5 from each of the differences between the observed and expected values.
C)At least double the amount of data should be collected.
D)The dependent variable needs to be collapsed into categories.

Question

Quizplus · Accepted Answer

Chi-square analysis is typically used to analyze categorical data, such as frequencies or proportions. In this case, the dependent variable (amount of physical activity) is measured in continuous minutes per week. Therefore, in order to use chi-square analysis, the researcher would need to collapse this variable into categories (e.g. low, moderate, high levels of physical activity). This can be done using predetermined cut-off points or by using quartiles of the distribution. Once the dependent variable is categorical, chi-square analysis can be used to compare the frequencies (or proportions) of the different types of interventions.

A Researcher Is Interested in Investigating 3 Types of Interventions