+ Reply to Thread
Results 1 to 2 of 2

Thread: Mann Whitney test interpretation

  1. #1
    Points: 1,365, Level: 20
    Level completed: 65%, Points required for next Level: 35

    Posts
    1
    Thanks
    0
    Thanked 0 Times in 0 Posts

    Mann Whitney test interpretation




    Hello I conducted Mann Whitney test to see if there is a significant difference in the duration spent by two groups (x,y) in a country ,and found that there is a significant difference in the median duration spent by these two groups (z=2.1 and P was less than 0.05)

    Which interpretation is correct (as I havenít done this test before)?

    Group x observed to have lower median of the years of stay in (the country) compared to the median of of the years of stay of those who are in group y, this difference was statistically significant (Z= 2.1, P= 0.03)
    Or:
    Respondents in Group x have spent shorter duration in (the country) (median, IQR=2 ,1.5-3.08) compared to those in group y (median, IQR=3 ,1.6-4), and the difference was statistically significant (Z= 2.107, P= 0.03).
    n.b: the duration was skewed, so I chosen MW test

  2. #2
    Points: 2,513, Level: 30
    Level completed: 43%, Points required for next Level: 87

    Posts
    194
    Thanks
    1
    Thanked 14 Times in 13 Posts

    Re: Mann Whitney test interpretation


    There isn't much difference between those two statements. Are you basically asking whether you can say "the values in group X are lower than the values in group Y" or only "the median value of group X is lower than the median value of group Y"?

    First, the answer isn't entirely clear-cut. The Mann-Whitney test statistic is certainly primarily sensitive to shifts in median, but it isn't only sensitive to shifts in median. If it were, you could directly compute U from the group medians, and you can't. In any case, you can't make the median lower without making any values lower, so it's not clear that the "values" formulation would be wrong even if Mann-Whitney were only about the median.

    Second, I don't know of anyone who would complain about either phrasing. They both accurately communicate the gist of the result, and for anyone who wants to get nit-picky about the precise meaning the quantiative test results are right there for all to see.

+ Reply to Thread

           




Similar Threads

  1. Mann-Whitney U test
    By awa in forum Statistics
    Replies: 1
    Last Post: 12-21-2010, 01:48 PM
  2. age and Mann-Whitney test
    By nurul in forum Statistics
    Replies: 1
    Last Post: 08-26-2010, 10:50 AM
  3. Mann Whitney U test
    By AdeleT in forum SPSS
    Replies: 0
    Last Post: 05-27-2009, 04:28 PM
  4. Help with Mann-Whitney U Test
    By vHeerda in forum Statistics
    Replies: 2
    Last Post: 10-23-2008, 08:50 AM
  5. Mann Whitney U Test problem
    By Thick As Treacle in forum Statistics
    Replies: 0
    Last Post: 08-18-2006, 03:45 PM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts






Advertise on Talk Stats