Correlation

• A correlation checks to see if two sets of numbers are related
• Any two variables producing quantitative data could be checked to establish whether a correlation exists
• Co-variables

  • each of the two sets of numbers represents a co-variable
  • once data has been collected for each of the co-variables
  • can be plotted in a scattergram and/or statistically analysed to produce a correlation coefficient
• Correlation Coefficient

  • a coefficient is a numerical way of indicating the strength of a relationship between two variables, it highlights the extent to which two variables correspond
  • the relationship between two variables will always produce a coefficient between 1 and -1
• Types of correlation

  • negative = co-variables do different things
  • positive = co-variables do the same thing
• Experiments vs Correlations

  • the most fundamental difference between the two is that experiments assess the effects of 1 variable (IV) on the DV which is measured
• Strengths of Correlation

  • very useful as a preliminary research technique
  • can be used to research topics that are sensitive/otherwise would be unethical, no deliberate manipulation of variables it required
  • by establishing a relationship between variables this enables us to predict future behaviour
• Limitations of Correlation

  • only identify a link; they do not identify which variable causes which, there may be a third variable present which is influencing one of the co-variables