Correlation

• • Correlation: Measures the extent of association between two variables. 
• • One variable is the predictor; the other is the outcome. 
• • Correlational studies: Involve obtaining and assessing two measures from participants to determine their association. 
• • Predictor variable: Occurs before and predicts the outcome variable. 

   
• Types of correlation: 

  • Positive correlation: Increase in one variable associates with an increase in the other. 
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  • Negative correlation: Increase in one variable associates with a decrease in the other. 
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  • Zero correlation: No relationship between variables. 
• • Correlation coefficient: A numerical score between 0 and 1 indicating the strength and direction of the relationship. 
  • Can be positive or negative  

   
• • Graphical representation: Scatter plots display correlations. 

   
• • Statistical test: Spearman’s rho can be used to determine the significance of the correlation. 

   
• • Causation: Correlation does not imply causation; a third variable might be involved.