Correlations

• what is correlational research ?

  It seeks to measure two variables to see of there is a relationship
• How is an alternate hypothesis used?

  Is a predictive statement made at the start such as

  As the weather gets hotter ice cream sales will increase
• A perfect positive correlation

  +1
• A perfect negative correlation

  -1
• Correlation co efficent

  • the near to 1 the stronger the relationship between the variables
• Strengths of correlational research :

  • good for finding relationships at the start of an investigation
  • and there are no participant variables as the same participant gives both scores
• Weaknesses of correlational research :

  • only suggests a relationship so it does not mean the two variables are causally related - results may be due to change
  • may be intervening variables that can explain the relationship
  • no cause and effect
  • data may be invalid because the measures may be artificial or unconnected
• Spearsmans Rho

  • rank the data for group A and B seperately
  • calculate the differences between the ranks from A and B
  • square each difference
  • add up all the squared differences
  • apply the equation