Which statistics should be reported before the results of a t test are reported? Suppose you read this statement: “The difference between the means is statistically significant at the .05 level (t = 2.333, df = 11).” Should you conclude that the null hypothesis has been rejected?

Results of t tests

Chapter Objectives
The reader will be able to:
–Know how the results of t tests are reported in various widely used forms such as a table or statement using various phrases and wordings
-Know the distinction between statistically significant and practical significance

Factual Questions
1. Which statistics should be reported before the results of a t test are reported?

2. Suppose you read this statement: “The difference between the means is statistically significant at the .05 level (t = 2.333, df = 11).” Should you conclude that the null hypothesis has been rejected?

3. Suppose you read this statement: “The null hypothesis was rejected (t = 2.810, df = 40, p < .01).” Should you conclude that the difference is statistically significant?

4. Suppose you read this statement: “The null hypothesis was not rejected (t = –.926, df = 24, p > .05).” Describe in words the meaning of the statistical term “p > .05.”

5. For the statement in Question 4, should you conclude that the difference is statistically significant?

6. Suppose you read this statement: “For the difference between the means, t = 2.111 (df = 5, n.s.).” Should you conclude that the null hypothesis has been rejected?

7. Which type of author seldom explicitly mentions the null hypothesis?
A. Authors of dissertations
B. Authors of journal articles

Notes
1. Practical significance is considered again in Chapter 30.
2. The .05 level is the “most liberal” in the sense that it is the level most likely to permit rejection of the null hypothesis. In other words, if a researcher uses the .01 or .001 levels, he or she is less likely to reject the null hypothesis than if the .05 level is used.