6.1: Hypothesis Tests and Types of Errors Flashcards
What is the focus on in hypothesis testing?
Examining how a sample statistic informs us about a population parameter.
What is Null hypothesis (or null) H0?
The hypothesis that is being tested.
What is Alternative hypothesis (Ha)?
The hypothesis that is accepted if the null hypothesis is rejected.
In a two-sided hypothesis test – the null hypothesis is…
Rejected in favor of the alternative hypothesis if the evidence indicates that the population parameter is either smaller or larger than a hypothesized value.
One-sided hypothesis test - occurs when the alternative hypothesis is…
Stated either as greater than or less than the hypothesized population parameter.
Type I error - …
The error of rejecting a true null hypothesis; a false positive.
Type II error - …
The error of not rejecting a false null hypothesis; false negative.
Level of significance (α) - the…
Probability of a Type I error in testing a hypothesis.
Confidence level (1 − α) - the…
Complement of the level of significance.
How can we decrease the probability of both error types?
By simultaneously increasing the sample size, n.
Power of a test - the probability of correctly…
Rejecting the null—that is, rejecting the null hypothesis when it is false.
The power of a test is, in fact, the complement of the…
Type II error.
What is a critical value?
Values of the test statistic at which the decision changes from fail to reject the null hypothesis to reject the null hypothesis.
What does statistically significant result mean?
It means that the null hypothesis can be rejected.
What is important to remember when working with null and alternative hypotheses?
Null hypothesis is never accepted; either the null is rejected on the basis of the evidence or there is a failure to reject the null hypothesis.
