The Chi-Square Test of Independence

Describe the chi-square test of independence. Give an example of a question that could
be answered using this test. If you were to assemble a contingency table, what would be
included in your rows and columns? Pick a cell of this contingency table and explain
what the value in the cell would represent (you do not need to give the value, just
explain what it would represent)? What hypothesis would be tested? What do you think
the answer would be? Why?

Describe the Chi-Square Test of Independence

The Chi-Square test of independence is a hypothesis test used mainly in social
sciences for both dependent and independent variables (Rodriuez, 1998). The purpose of the
Chi-Square test of independence is to check the dependence or independence of two
variables. To do this, the test examines the relationship between the scores for the two
categorical variables using a classification table, also called a contingency table (Rodriuez,
1998). As this paper will show, the two variables under examination are assumed to have no
relationship through a null hypothesis, while the alternative hypothesis assumes some
measure of relationship (Rodriuez, 1998). An example of a problem where a Chi-Square test
of independence would be applicable is studying the relationship between gender and
participation in a public protest. There are a million people in a city and a sample of 100
eligible protestors is picked for the study. The results of this study are presented in a two by
two contingency table as follows:

Male Female

Did Not Participate
In this example, the Chi Square test checks whether being male or female (columns)
is independent of the rows (participating in a public protest).

Describe the Chi-Square Test of Independence 2

To answer the question above, a test hypothesis is built. The null hypothesis in this
case is that gender and participating in a public protest are independent. Therefore, the
alternative hypothesis is that participating in a public protest and gender are dependent.
I think the results for this study would reject the null hypothesis. This means that the
data proves the alternative hypothesis true. In other words, participating in a protest and
gender are dependent.

Describe the Chi-Square Test of Independence 3



Rodriuez, C. (1998). Chi-Square Test for Independence.