correlation

• correlation techniques


  is a non-experimental method used to measure how strong the relationship is between two (or) co-variables

  in correlation studies the movement and direction of co-variables in response to each other is measured
• correlation real world example

  it was noticed that there was a positive correlation between smoking and lung cancer

  later research was extended and there was a cause and effect discovered
• positive correlation

  occurs when one co-variable increases (ice cream sales increases as temp increases)

  strong or weak positive
• negative correlation

  when one co-variable increases and one decreases (raincoat sales decreases as sun increases)

  strong and weak correlation
• zero correlation

  no distinct relatiohsip
• correlation coefficient

  +1 (perfect positive correlation)

  -1 (perfect negative correlation)

  0.8 is generally accepted as strong positive
• how are correlations represented

  scattergram
• correlation strengths

  relatively quick to carry out and there is no need for a controlled environment

  secondary data can be used meaning its less time consuming
• correlation limitations

  lack experimental manipulation and control

  can't demonstrate cause and effect