1. Chapter 7: Statistical Issues in Research planning and Evaluation
SFM 651:
Research Methods
Dr. Johnson

2. Probability The odds a certain event will occur
Relative frequency – getting it close
Coin toss – 50-50
Actuality – or 51-49

3. Alpha α Level of probability set by the experimenter before the study
Also called level of significance
Usually .05 or .01
Findings due to chance 5% or 1% of the time.

4. Beta β Magnitude of type II error
Acceptance of the Null hypothesis when it is false
When Alpha is lower, Beta gets higher.

5. Meaningfulness Importance of significance of the effect Effect size
Difference between means divided by Standard deviation

6. Power Probability of making the correct decision
Reject Null Hypothesis when it is false.
The greater the power, the more likely it is that you will see a difference.

7. Ways to obtain more power
Increase sample size
# of participants
Becomes easier to know what will actually happen with more samples.