1. Myers Chapter 1 (F): Statistics in Psychological Research: Measures of Central Tendency
A.P. Psychology

2. Do-Now: (In Journal) What are statistics?
Why are statistics important in social sciences?
How are the following measures of central tendency found?
Mean
Median
Mode

3. Statistics in Psychology
The collection, classification, analysis, and interpretation of numerical psychological data
Descriptive Statistics:
Describes collected data
Frequency Distribution:
Bar Graph
Histogram

4. 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

5. Statistics in Psychology
Can you think of another example of Nominal and Ordinal data?

6. 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. Height/weight

7. Statistics in Psychology
Can you think of another example of Interval and Ratio data?

8. 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

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

10. Distributions Skewed Distribution:
Positively skewed; “Skewed to the Right”
Negatively skewed; “Skewed to the Left”

11. Distributions
What types of situations might cause a “positively-skewed” distribution?
What types of situations might cause a “negatively-skewed” distribution?

12. Positively Skewed Distribution
Distributions
Positively Skewed Distribution

13. Review Differentiate between the following types of data:
Nominal
Ordinal
Interval
Ratio
What is a normal distribution?
What is the difference between a positively and negatively-skewed distribution?

14. Homework Unit 2 FRQ Unit 2 Test: “Research Methods”
Chapter 2 Outline: “The Biology of Mind”