← Every exhibit

Table Table 2 From the research bench

Decision Errors and Statistical Power

DecisionNull hypothesis trueTreatment effect real (lift)
Reject the null (declare a winner)Type I error (alpha): a false positive, about 5% of the timeCorrect decision (power, one minus beta): a true discovery, 80% to 90% of the time
Fail to reject (retain the control)Correct decision (one minus alpha): a true negative, about 95% of the timeType II error (beta): a false negative, 10% to 20% of the time

Swipe or scroll horizontally if the table is wider than your screen.

Cite Embed

Reference & Evidence

Source: Table from this essay. Sources and interpretation are given in the article.