Correlation

• Correlation


  • Mathematical technique
  • illustrates the strength and direction of a relationship between co-variables
  • plotted on a scatter gram
• Difference between a correlation and an experiment

  Experiment:

  • IV is controlled and manipulated
  • DV is measured Correlation:
  • No manipulating variables
  • Cannot establish a cause and effect relationship
• Correlation hypotheses


  • Directional= There is a negative/ positive correlation between co-variables 1 and 2
  • Non-directional= There is a correlation between co-variable 1 and 2
  • Null= There is no correlation between co-variable 1 and 2
• Correlation coefficients


  Indication of the direction and strength of the relationship between 2 variables

  
• Strengths of correlations

  • useful for research: quantifiable and precise data
  • Quick and economical
• Weaknesses of correlations


  • Does not say why variables are related
  • Possibility that the relationship is caused by a 3rd unknown variable
  • can be misinterpreted or misused