CORRELATIONS

• Correlation


  Not a research method, rather an analysis of the relationship between co-variables
• Correlational research


  1. Variables are not manipulated

  2. Two co-variables are measured and compared to look for a relationship

  3. One or both co-variables may be pre-existing
• Scattergraph


  A plot of the two scores for each participant as one point
• Scattergraph outcomes


  • Positive correlation: One co-variable increases as does the other
  • Negative correlation: One co-variable increases while the other decreases
  • Zero correlation: No relationship between the variables
• Correlation coefficient


  Represents the direction and strength of the relationship between co-variables, expressed as a value between -1 and +1
• A perfect positive correlation would be expressed as +1
• A perfect negative correlation would be expressed as -1
• No relationship would be expressed as 0
• Correlation coefficient descriptions


  Weak, moderate or strong
• Strengths of Correlational Analysis

  • They are able to show relationships between variables
  • The data may be easily available for researchers to quickly analyse
  • Allows predictions to be made when looking at the relationships between co-variables
  • Due to the data being readily available, there are unlikely to be any ethical issues
• Limitations of Correlational Analysis

  • They do not show causation
  • Extraneous relationships with other variables may affect the co-variables and the outcome
  • Correlations work well for linear relationships but are less successful when dealing with non-linear relationships
• Experiments


  Involve deliberate manipulation of the independent variable to measure the impact on the dependent variable
• Correlations


  There is no deliberate manipulation of any variables, both variables may impact each other and we measure the degree to which this happens
• Correlation does not always mean causation
• Neither experiments nor correlations are better or worse, it depends on the context and situation being investigated