Question

5. True or False: In a research study, the alpha () and the p-value are two names for the same thing. (5)

a. True

b. False

Answer 1

Option (b) False

In conducting a test of significance or hypothesis test, there are two numbers that are easy to get confused. These numbers are easily confused because they are both numbers between zero and one, and are both probabilities. One number is called the p-value of the test statistic. The other number of interest is the level of significance or alpha. We will examine these two probabilities and determine the difference between them

Difference Between P-Value and Alpha

To determine if an observed outcome is statistically significant, we compare the values of alpha and the p-value. There are two possibilities that emerge:

The p-value is less than or equal to alpha. In this case, we reject the null hypothesis. When this happens, we say that the result is statistically significant. In other words, we are reasonably sure that there is something besides chance alone that gave us an observed sample.

The p-value is greater than alpha. In this case, we fail to reject the null hypothesis. When this happens, we say that the result is not statistically significant. In other words, we are reasonably sure that our observed data can be explained by chance alone.