Correlational Method

• What is Correlation?


  A correlation measures the relationship between two co-variables - e.g. the relationship between ice cream consumption and crime.
• What does Correlation not show?


  Cause and effect.
• What can the relationship be?


  Positive and Negative.

  Weak and Strong.
• How can a correlation be represented? 


  On a scattergram, analysed using a Spearman’s Rho or Pearson R and provides quantitative data.
• What is a positive correlation?


  A positive correlation is a relationship between two co-variables where they both increase or decrease together.
• What is a negative correlation?


  When two co-variables move in opposite directions, such that an increase in one variable is associated with a decrease in the other variable.
• What is a correlation coefficient? 


  A number from -1 to +1 that indicates the strength and direction of the relationship between variables. The correlation is usually represented by the letter r.
• Scattergrams:


  One variable is placed on the x axis (horizontal axis) and the other variable is placed on the y axis (vertical axis). By plotting variables against each other we can show their correlational relationship.
• Writing a Correlational Hypothesis:


  1. You should never use the word difference or effect.
  2. You should always use the word correlation or relationship.
  3. You should not use the terms IV or DV because a correlation has 2 co-variables.
  4. Co-variables should be fully operationalised.
  5. You need quantitive data from both co-variables to be able to do a correlation.