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# Correlation Tutorial

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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.

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### Correlation Tutorial

1. 1. Analyzing Statistics American River College Professor Hokerson
2. 2. Using this Tutorial • Use the navigation buttons across the bottom of the screen. • Click on hyperlinks when prompted • Have fun and learn!
3. 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. 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. 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. 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. 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. 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. 9. DESCRIBING CORRELATION Correlations describe the nature of the relationship between variables. There are 2 types of correlations
10. 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. 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. 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. 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. 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. 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. 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. 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. 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.
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