Confidence level is 1 − α where α is the ______.

Confidence level is 1 − α where α is the ______.

• A. Type I error rate
• B. Significance level
• C. Power
• D. Critical value

Answer: (B)

The concept here is how the risk of making a false rejection is linked to confidence. α represents the probability of rejecting a true null hypothesis, which is the Type I error. The confidence level is defined as 1 minus that risk, so a 95% confidence level corresponds to α = 0.05. The standard term for α in this context is the significance level, because it sets the cutoff used to judge whether results are statistically significant. So the blank is filled with significance level. While “Type I error rate” describes the actual probability of that error, the conventional label used when talking about the threshold for significance is the significance level.

The concept here is how the risk of making a false rejection is linked to confidence. α represents the probability of rejecting a true null hypothesis, which is the Type I error. The confidence level is defined as 1 minus that risk, so a 95% confidence level corresponds to α = 0.05. The standard term for α in this context is the significance level, because it sets the cutoff used to judge whether results are statistically significant. So the blank is filled with significance level. While “Type I error rate” describes the actual probability of that error, the conventional label used when talking about the threshold for significance is the significance level.