1. Basic Statistical Review
EPS 625 – Intermediate Statistics
Robert A. Horn, Ph.D.

2. The Decision Tree

3. Key Terms Sample Population Sampling Statistic
Representative of the population
Commonly symbolized with Roman Letters
Population
Parameter
Commonly symbolized with Greek Letters
Sampling
Random Sample
Random Assignment

4. Measurement Scales

5. Key Terms Variables Categorical (Nominal – Ordinal)
Discrete
Qualitative
Frequency
Continuous (Interval – Ratio)
Quantitative
Measurement

6. Key Terms Independent (Predictor) Variable
Active (experimental)
Attribute (measured)
Dependent (Criterion) Variable
Extraneous Variable
Confounding
Third Variable

7. Key Terms Descriptive Statistics Inferential Statistics
Measures of Central Tendency
Mean, Median, Mode
Measures of Variability
Range, Standard Deviation, Variance
Inferential Statistics
Parametric
Nonparametric

8. Frequency Distributions

9. Graphing Data – Constructing a Graph

10. Distorting Data Through Graphing

11. Bar Graphs (Categorical Data)

12. Histograms (Continuous Data)

13. Stem-and-Leaf Displays

14. Boxplots

15. Describing Distributions
Symmetric (Normal Distribution)
Modality
Unimodal, Bi-Modal, Multi (tri)-Modal
Skewness
Negative, Normal (Symmetrical), Positive
Kurtosis
Platykurtic, Mesokurtic (Normal), Leptokurtic
Linearity
Linear or Curvilinear

16. Describing Distributions

17. Describing Distributions

18. Describing Distributions

19. The Normal Distribution

20. Summation Notation ()
One of the most common symbols in statistics is the uppercase Greek letter sigma, (), which is the standard notation for summation.
It is readily translated as “add up, or sum, what follows.”
The general rule, which always applies, is to perform operations within parentheses before performing operations outside parentheses.

21. Common Statistical Symbols
X A Raw Score
Mean of a Sample
 Mean of a Population
s Standard Deviation of a Sample
 Standard Deviation of a Population
s 2 Variance of a Sample
2 Variance of a Population

22. Key Terms Probability Confidence Intervals Effect Size Standard Scores
 = Level of Significance
p = Probability (Sig.)
Confidence Intervals
Effect Size
d Family
r Family
Standard Scores z 

23. Hypothesis Testing

24. Non-Directional (two-tailed)

25. Directional (one-tailed – negative end)

26. Directional (one-tailed – positive end)

27. Statistical Results and APA
t(9) = 5.08, p < .05, d = 1.61
F(2, 57) = 9.75, p < .01, 2 = .42
| = Single Space
NOT
t(9)=5.08,p<.05,d=1.61
F(2,57)=9.75,p<.01,2=.42