1. Not finding help here? Sign up for a free 30min tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

How to count Spearman Rank order correlation

  1. May 8, 2013 #1
    1. The problem statement, all variables and given/known data
    calculate the rank order correlation between the following data:

    6, 5, 4, 2, 3, 3, 8, 3, 7, 6, 7, 5, 5, 4, 2, 7, 6, 2, 4, 6

    4, 3, 6, 7, 6, 7, 1, 9, 1, 2, 3, 4, 5, 5, 7, 1, 2, 9, 5, 4


    2. Relevant equations

    Following the output from http://www.vassarstats.net/corr_rank.html, given the ranks, then from each individual rank subtract the equivalent opposing / matching rank. Lastly, raise every subtraction to the power of two and sum up results:

    Ʃ( #x[itex]_{i}[/itex] - #y[itex]_{i}[/itex] )[itex]^{2}[/itex]

    3. The attempt at a solution

    I have used the aforementioned online site to help my calculations, and have used the ranks given there, from the appropriate variables, to perform the previously described actions.

    The answer is ≈ -0.93. This is confirmed by vassarstat.net. However, vassarstat does not give any explanation how to perform the rest of the problem.

    I can only get ≈-0.90. After Ʃ( #x[itex]_{i}[/itex] - #y[itex]_{i}[/itex] )[itex]^{2}[/itex], I get 2529. Then I use the spearman rank order correlation equation 1 - [itex]\frac{6 * 2529}{20 * (20^{2} - 1)}[/itex] ≈ -0.90
     
  2. jcsd
  3. May 9, 2013 #2
    Anyone? Exams are just behind the corner and I can not figure this one out. Hate it if they would ask to use this in the test. It could be so simple if i could just understand
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted