correlation

• what is correlation?

  -method for finding out if 2 variables are related

  -it doesnt look for differences but looks to see how much two things go together

  -correlations do not identify cause and effect

  -they reveal the type of relationship
• what is positive correlation?

  -involves both variables increasing or decreasing in value in the same direction
• what is negative correlation?

  -involves both variables increasing or decreasing in value in the opposite direction to each other
• strength of a correlation:

  -a correlation provides a value between 0 and 1: the higher the value the stronger the correlation

  -0 to 2 is a weak correlation

  -0.4 to 0.6 is a moderate correlation

  -0.8+ is a strong correlation
• scattergraphs:

  -correlation data is always presented by using a scattergraph

  -a very strong correlation would produce a pattern with the line starting at the bottom left to the top right

  -a very negative correlation would produce a pattern with the line at the top left and goes down to bottom right
• what are the strengths of using correlations?

  1. they are useful for establishing the existence of relationships between variables
  2. enables research to be conducted in socially sensitive areas since it does not manipulate any variables
• what are the weaknesses of using correlations?

  1. does not establish cause and effect
  2. the relationship found by a correlation is linear and they cannot show the different changes in direction