Statistical Inference and Hypothesis Testing Exam 1 Flashcards
1
Q
Alternate hypothesis (HA)
A
actual hypothesis
2
Q
Null hypothesis (H0)
A
- Null hypothesis (H0):
- Conclusions are made in terms of rejecting or failing to reject the null hypothesis
3
Q
Alpha
A
- Probability of a Type I error
- Reject the null when the null is true
- Conclude there is a difference when none exists
- False positive
- Confidence = 1-α
4
Q
Beta
A
- Probability of a Type II error
- Fail to reject the null when the null is false
- Conclude there is no difference when one actually exists
- False negative
- Power = 1-β
5
Q
Power
A
Probability of concluding there is a difference when one actually exists
6
Q
a priori
A
alpha and beta are thresholds set by researchers before any data is collected; determined by literature or clinical relevance
7
Q
p value
A
- Calculate p value by calculating the z score
- A z score has a corresponding p value
- p < 0.05 : H0 is rejected
- p > 0.05 : H0 fail to be rejected
8
Q
Non-directional tests and examples
A
- two tailed, look in both directions
- Test of difference
- Test of equivalence
- Null is opposite of the type of test -> rejecting it would say that the type of test is true
9
Q
Tests of difference
A
- Tests whether the difference between two quantities is 0
- H0 : X-Y = 0
10
Q
Tests of equivalence
A
- Tests whether two quantities are within an acceptable range of each other
- H0 : |X-Y| ≥ Δ
11
Q
Directional tests and examples
A
- one tailed, looks only in one direction
- Test of superiority
- Test of non-inferiority
12
Q
Tests of superiority
A
- Tests whether one quantity is greater than or less than the other
- H0 : X-Y ≤ 0
- Rejecting the null says that one group is greater than (or less than) the other
13
Q
Tests of non-inferiority
A
- Tests whether one quantity is no worse than a second quantity
- H0 : X-Y ≥ Δ
- Rejecting the null says the one group is noninferior to the other
14
Q
How do you approach hypothesis testing?
A
- Convert the research question into appropriate null and alternate hypotheses
- Select the appropriate statistical test
- Select the desired significance level and the appropriate critical value for the statistical test
- Calculate the test statistic
- Compare the test statistic to the critical value and draw conclusions
15
Q
How do you go about testing the null hypothesis?
A
- Temporarily assume H0 is true
- If data determines that H0 is extremely unlikely, this provides evidence against H0 and we reject H0
- If data determines that H0 is not extremely unlikely, this does not provide evidence against H0 and we fail to reject H0
