1. Ms. Saint-Paul A.P. Psychology
Unit 2 (M8): Statistics in Psychological Research: Measures of Central Tendency
Ms. Saint-Paul
A.P. Psychology

2. Statistics in Psychology
The collection, classification, analysis, and interpretation of numerical psychological data
Descriptive Statistics:
Describes collected data
Frequency Distribution: ( How much sleep high school students get every night))
Bar Graph
Histogram

3. Statistics in Psychology
Types of Psychological Data:
Nominal:
Categorical
Non-numerical; cannot compute mean
Bar graph
(E.g. Favorite ice cream flavor)
Ordinal:
Ordered
(E.g. 1st place, 2nd place, 3rd place)

4. Statistics in Psychology
Types of Psychological Data:
Interval:
Equal interval between points;
no true zero point
Numerical; can compute mean
Histogram
(E.g. Degrees in Fahrenheit)
Ratio:
true zero point
E.g. the recipe for making pancakes is 3 cups of flower and 2 cups of milk. So the ratio is 3:2

5. Likert Scale

6. Commuting Likert Scale in Spss

7. Measures of Central Tendency
Mean:
The arithmetic average of a distribution
Obtained by adding all scores together, and dividing by the number of scores
Median:
The middle score of a distribution
Half of the scores are above it and half are below it
Mode:
The most frequently occurring score(s) in a distribution

8. Distributions Normal Distribution:
Symmetrical, Bell-shaped distribution
Mean, Median, Mode all are the same

9. Measures of Variation Range: Standard Deviation:
The difference between the highest and lowest scores in a distribution
higher range = greater spread
Lower range= less spread
Standard Deviation:
Distance between each score from the mean
Great accuracy because all score are involve in the calculation.

10. Do-Now: (In Journal)
Differentiate between the following types of data:
Nominal
Ordinal
Interval
Ratio
What is a normal distribution?
What are statistics?
Why are statistics important in social sciences?
How are the following measures of central tendency found?
Mean
Median
Mode