- Hypotheses
- Alternative Hypothesis -
- Null Hypothesis -
- Decisions
- assume Ho is true and calculate the probability of getting the results by chance alone
- If the obtained probability is equal to or less than a critical probability (alpha level) we reject Ho/ thus accepting H1
- If greater fail to reject/retain Ho
Binomial Distribution
When considering chance alone p = .50
Use table compare to alpha = .05
Error Types
Type I - decide to reject Ho when Ho is false
Type II - decide to retain Ho when Ho is true
|
|
State of Reality |
|
Decision |
H0 is true |
H0 is false |
|
Retain H0 |
Correct Decision |
Type II error |
|
Reject H0 |
Type I error |
Correct Decision |
Alpha Level - probability of making a Type I error, set in advance
Consequences
Tend to use .05 or .01
Evaluate the Tail of the Distribution
Refer to table
One vs. Two tails
Size of Effect: Significant vs. Important
If reject Ho then results are significant