This tutorial corresponds with Module A Lesson 2 and should be completed by students enrolled in Professor Hokerson's Psychology 300 online class at American River College.

1. Analyzing Statistics
American River College
Professor Hokerson

2. Using this Tutorial
• Use the navigation buttons across the bottom of the
screen.
• Click on hyperlinks when prompted
• Have fun and learn!

3. Table of Contents
• Objectives
• Module A Objectives #17 and 18
• Action Items
• Scientific Method
• Statistical Significance
• Explaining Correlation
• Describing Correlation
• Research Examples
• Conclusions

4. MODULE A OBJECTIVES
By the end of this tutorial you will be able to…
# 17 – Explain the correlation coefficient.
# 18 – Identify examples of positive and negative correlations.

5. Why use the scientific method?
• Read about the steps
of the scientific method
in pages 16-19 of our
textbook.
• Method
• Formulate
• Design
• Analyze
• Report
1. By using this method…
2. You can achieve these goals!
• Goals
• Describe
• Explain
• Predict
• Control
Wait! But you can’t achieve these
goals until you analyze the data!

6. SCIENTIFIC ASSUMPTIONS
Researchers must first make several assumptions…
1. All events are lawful.
• This assumption allows for researchers to make the next one.
2. Behavior and mental processes follow consistent patterns.
• This assumption allows researchers to conclude that variables
somehow correlate or have causal relationships.
Hint! Statistical significance and correlation are a few of the many
statistics used to achieve the goals of the scientific method!

7. STATISTICAL SIGNIFICANCE
Review: Chapter 1 – Step 3. Analyze the Data and Draw Conclusions
(pages 18 – 19).
Question: Why do researchers calculate statistical significance?
Answer: If a researcher wants to achieve the goals of the scientific
method (which is the whole point in conducting research) then he/she
needs to be able to show that the correlation (or cause) is real, as opposed
to have occurred by chance.
Does watching violent video games contribute to violence?
Does pre-marital counseling predict divorce rates?
Does day care lead to behavioral problems?
Do mandatory break periods increase work productivity?
Wouldn’t it be nice to know that these correlations were true as opposed to
random occurrences? That’s why significance is important!

8. EXPLAINING CORRELATION
• Read Chapter 1 (pages 24 – 25)
• Tip: One way you should be able to interpret statistics to help
explain the nature of the relationship that exists (or not) between
variables is the Correlation Coefficient!
• Summary: The Correlation Coefficient identifies the strength of
the relationship between variables and is represented by a
number on this spectrum between -1.0 and +1.0
• Tip: The correlation coefficient can never be a number larger
than 1.0 or smaller than -1.0.

9. DESCRIBING CORRELATION
Correlations describe the nature of the relationship between variables.
There are 2 types of correlations

10. POSITIVE CORRELATION
As one variable increases,
so does the other.
The chart to the right
shows that as IQ score
increases, average salary
also increases.
----OR-----
As one variable
decreases, so does the
other.
The Chart to the right
shows that as levels of
stress decrease, number
of altercations with a
spouse also decreases.

11. NEGATIVE CORRELATION
As one variable increases,
the other. variable
decreases
The chart to the right shows
that as the number of hours
in therapy increases, the
occurrence of ADHD
symptoms decreases.
In the chart to the right, as
hours spent watching TV
increases, number of
retained vocabulary
decreases.

12. RESEARCH EXAMPLES
• Read the following research vignettes - do they
describe a positive or negative correlation?
• A study reported that babies and infants that watch programs geared
toward enhancing intelligence use fewer words than their non-
program watching cohorts.
• A study reported that adults who spend more time talking with their
spouses report higher levels of marital satisfaction.
• A longitudinal study reported that factors such as motivation,
creativity, and willingness to work hard are predictors of academic
success.
• A study reported that the more friends a person has the lower his self-
esteem.

13. RESEARCH EXAMPLE 1
• A study reported that babies and infants that spend more time
watching programs geared toward enhancing intelligence use
fewer words than their non-program watching cohorts.
• Question – is this a positive or negative correlation?
• Variable 1 = Watching TV – is it increasing or decreasing?
• Variable 2 = Word count – is it increasing or decreasing?
IF both variables are
increasing it is a POSITIVE
correlation
IF one variable is increasing and
the other decreasing, it is a
NEGATIVE correlation

14. RESEARCH EXAMPLE 2
• A study reported that adults who spend more time talking with
their spouses report higher levels of marital satisfaction.
• Question – is this a positive or negative correlation?
• Variable 1 = Talking – is it increasing or decreasing?
• Variable 2 = Marital satisfaction – is it increasing or decreasing?
IF both variables are
increasing it is a POSITIVE
correlation
IF one variable is increasing and
the other decreasing, it is a
NEGATIVE correlation

15. RESEARCH EXAMPLE 3
• A longitudinal study reported that factors such as motivation,
creativity, and willingness to work hard are predictors of
academic success.
• Question – is this a positive or negative correlation?
• Variable 1 = Motivation – is it increasing or decreasing?
• Variable 2 = Grades – is it increasing or decreasing?
IF both variables are
increasing it is a POSITIVE
correlation
IF one variable is increasing and
the other decreasing, it is a
NEGATIVE correlation

16. RESEARCH EXAMPLE 4
• A study reported that the more friends a person has the
lower his self-esteem.
• Question – is this a positive or negative correlation?
• Variable 1 = Number of friends
• Variable 2 = Self-esteem – is it increasing or decreasing?
IF both variables are
increasing it is a POSITIVE
correlation
IF one variable is increasing and
the other decreasing, it is a
NEGATIVE correlation

17. CONCLUSIONS
The scientific method is the foundation for studying psychology.
1. It allows us to describe how variables relate, or don’t relate.
2. It allows us to conclude when one variable causes another.
3. It allows us to generalize the results of a small study to a much
larger population.
4. It allows us to replicate findings in future studies.

18. MODULE A OBJECTIVES
After completing this tutorial you should be able to…
# 17 – Explain the correlation coefficient.
# 18 – Identify examples of positive and negative correlations.