Correlations

• What is the purpose of correlations in research?

  To investigate the relationship between two co-variables
• What are co-variables?

  Variables examined for a relationship
• How does a correlation differ from an experiment?

  A correlation looks for a relationship
• What are the types of correlation?

  • Positive correlation: one increases, the other increases
  • Negative correlation: one increases, the other decreases
  • Zero correlation: co-variables are not related
• What does a positive correlation indicate?

  As one variable increases, the other increases
• What does a negative correlation indicate?

  As one variable increases, the other decreases
• What does zero correlation mean?

  Co-variables are not related
• What is the correlation coefficient?

  A statistic measuring strength and direction
• What does the correlation coefficient value represent?

  It is always given the value r=
• What are the strengths and limitations of correlations?

  Strengths:

  • Precise quantitative measure of relationships
  • Can measure non-manipulatable variables
  • Useful preparatory investigation

  
  

  Limitations:

  • Cannot establish causation
  • Possible intervening variables