Correlational Research

I. Correlational strategies

A. Design issues - correlational vs. experimental strategies

 

 

 

 

B. Correlation Coefficients

1. Scatterplots

 

 

 

2. Positive and Negative (inverse) linear relationships

 

 

 

   

 

3. Curvilinear relationships

 

 

 

 

4. Calculating Pearson r (correlation coefficient)

 

 

 

 

II. Problems with interpreting correlations

A. restricted range

 

 

B. outliers

 

 

C. lack of reliability

 

 

D. correlation vs. causation

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