spearmans rank

• what is spearmans rank used for?

  it is used to test for a relationship between two sets of data, allowing you to accept or reject a null hypothesis that there is no relationship between the data sets
• what are the advantages of using spearmans rank?

  quick and easy to calculate

  numerical value is easy to analyse:

  a final value closer to 1 means there is a positive correlation, with 1 being a perfect positive correlation

  if the final value is closer to -1, there is a negative correlation, with -1 being a perfect negative correlation

  if the final value is 0, there is no relationship between the variables

  spearmans rank is less affected by extreme values, as it does not rely on actual data values

  the result can be further analysed with a scattergraph, or by calculating the line of best fit
• what are the disadvantages of using spearmans rank?

  a suitable size of data set is necessary (at least 8)

  the result does not tell you what causes the relationship, just whether there is one

  the method is not as accurate or as powerful as pearsons, because it hides the differences in the actual values by ranking