Correlations and scatter graphs

• What is the purpose of a correlational study?

  To establish relationship between two variables
• How do correlational studies differ from experiments?

  They do not involve IV or DV
• What are the two ways to analyse the relationship between co-variables?

  Scatter graph or correlation coefficient
• What term describes the variables examined in a correlational study?

  Co-variables
• What are the two types of correlations?

  • Positive: As one variable rises, so does the other
  • Negative: As one variable rises, the other falls
• What happens to G-forces as a jet pilot flies faster?

  G-forces get higher
• What statistical method assesses the strength of a correlation?

  Correlation coefficient
• What range does a correlation coefficient lie between?

  1 to -1
• What does a correlation coefficient of 0 indicate?

  No relationship
• What does a correlation coefficient of 1 indicate?

  Perfect positive correlation
• What does a correlation coefficient of -1 indicate?

  Perfect negative correlation
• What are the advantages of correlational studies?

  • Allows researcher to see strength and direction of a relationship
  • Can be used when variables cannot be manipulated
• When would it be appropriate to use a correlational study?

  When manipulating variables is unethical
• What are the disadvantages of correlational studies?

  • Do not show cause and effect
  • Other unknown variables may cause change
• What common error do people make when interpreting correlations?

  Assuming cause and effect