Correlations

• What is a correlation?

  refers to the measurement of a relationship between two or more variables

  - the variables measured are known as co variables

  - correlations are always represented on scatter graphs
• Positive correlation


  as one variable increases, so does the other
• Negative correlation


  as one variable increases, the other decreases
• Zero correlation


  no relationship exists between variables
• Weaknesses of correlations


  - correlations tell us that two variables are related, they do not tell us how those variables are related

  - intervening variables may be overlooked, correlations ignore a potential third factor
• Strengths of correlations


  - correlations tell us that two variables are related

  - correlations can be used to investigate complex relationships