McNemar Test Example

Using the McNemar Test - A Real-World Example

The scenario

At a clinic designed to assess purchase consideration, respondents were asked to evaluate two prototype products. After the evaluation was completed, each respondent was asked whether he or she would consider purchasing each prototype. The table below shows that 152 respondents agreed that they would consider purchasing both products. Another 155 respondents agreed on both products, saying that they would not consider either one. The McNemar test uses only two cells: the 31 respondents who would consider Prototype A but not B, and the 61 respondents who would consider prototype B but not A.

The data

		Consider Purchasing Prototype B
		Yes	No
Consider Purchasing Prototype A	Yes	152	31
Consider Purchasing Prototype A	No	61	155

Entering the data into Maritz Stats

Enter the Yes/No and No/Yes counts into the form.

We choose the default confidence level of 95%, so we just leave that.

Once we have entered everything, we click Test! and see the results:

The results are statistically significant at the 95% level of confidence. We therefore reject the null hypothesis that no difference in purchase consideration for these two prototypes exists.