# Exercise 7 ( Set 1 ) Essay

1. What are three versions of the null hypothesis?

The three versions of the null hypothesis are: (1) “the observed difference was created by sampling error”, (2) “there is no true difference between the two groups” and (3) “the true difference between the two groups is zero.” (Barker, 56-57)

2. Is the null hypothesis typically stated in social scientific research? Why/why not?

The null hypothesis is not usually stated in social scientific research. Researchers rarely state the null hypothesis in their academic journals because they “assume that readers know the sole purpose of a significance test is to test a null hypothesis.” (Barker 57) Instead of reporting the null hypothesis, researches “report which differences were tested for significance, which significance test they used, and which differences were found to be statistically significant.” (Barker 57) Additionally, researchers are more likely to state the null hypotheses in the theses and dissertations to help ensure that students understand why the researches have conducted a significance test.

3. p < .05 is the most commonly accepted bench mark for statistical significance. What does statistical significance tell us?

The statistical significance of p< .05 tells us what the probability that something is true are less than 5 in 100, which means that it is likely that it is not true. If the significance test shows that the probability that something is true is less than .05, we are able to reject…