mann-whitney

  1. R

    Point-biserial correlation when some of the test assumptions is violated

    Hi! I originally posted my question on StacExchange-CrossValidated, but no one there seems to be able to answer my question. This is the situation: I've got 15 raters who assess if there is deep invasion of a cancer type or not (dichotomous), and they can be either accurate or inaccurate...
  2. S

    Looking for help with the Mann-Whitney U Test

    Hey, I'm a highschool student finishing up with AP Statistics. In my final project, I am using the Mann-Whitney U Test to compare two un-normal data sets, but this test is beyond the scope of the course, and I have never really learned how to do it. The descriptions I have found on how to carry...
  3. E

    3 values ordinal variable: Mann-Whitney or Chi-squared?

    Hello, I have an ordinal variable which assumes only 3 values. I need to do a comparison between 2 treatments. I used Mann-Whitney test, since is an ordinal. My "p-value" is quite high (0.9388) which is strange because the values distribution is quite different for each group. Then I...
  4. J

    Mann-Whitney U Test: Ordinal data with few categories

    Hello, I am trying to use the Mann-Whitney U Test to compare ordinal data between 2 groups, but the problem is that there are only 3 categories for my ordinal data. I have never seen the Mann-Whitney U Test be used on ordinal data with fewer than 5 categories. So I was wondering, what is the...
  5. T

    Mann Whitney help

    Hi, I did a small experiment and I had 4 distribuitons. these are not normal distribuitions, that is why my professor told me to run a Man Whitney test. She said something about that I need to reject one of the 3 hypothesis that are involved in this field of research. I have no idea...
  6. F

    Best Nonparametric test for nominal and continuos variables

    Hello everybody. I'm looking for the best test to find an association between two variables: - a test score (continuous, ranging from 0 to 100); - a yes or no binary variable (like, for instance, being clever or not) Variables are not normally distributed and their relation is not...
  7. D

    Research methods - Comparing high and low risk sports

    I am currently conducting a piece of research that aims to find if there is a difference between personality traits between participants of high and low risk sports. I have collected personality questionnaires which have collected information on the respondents personalities (5 factors) I...
  8. P

    How to compare a small sample to a large control group sample?

    Hello, The prupose of my research was to measure the impact of a dropout prevention program. I used a survey consisting mostly of Likert scales and I compared the answers to a control group. The control group was relatively large, as it was based on a government study of roughly 1500...
  9. N

    Can you compare 3 small groups <4 participants using Multiple Mann-Witney?

    Hi, I am very new to statistics but have found myself doing a small master desgree research project with very little statistics background so I am finding it very difficult. I have had a go at a mann-whitney but am just not confident that it is the correct test to use or whether there is...
  10. A

    Quick SPSS testing question

    Hi, I have a data set with two questions: - whether one visits coffee chains or independent coffee stores - results are set within 1 (chains) and 2 (independent) --- (for which I have 106 for chains and 24 for independents equalling a total of 130 responses) - whether these locations have a...
  11. Junes

    Comparing museum visitors numbers using non-parametric method

    Hi all, I'm supervising a student who is going to do her research on visitor numbers to a certain exhibition. The museum will be actively promoting this exhibition in the month to come. The museum wants to know whether this marketing campaign had an effect on visitor numbers. So, we...
  12. V

    High Mann-Whitney U number good or bad?

    Hello all! I'm quite the newbie with statistics so I'm probably asking stupid questions, but I've been googling now for quite a while without success. I've analysed newspaper stories and one of the variables is how many photographs they contained. I have two distinct paper groups from two...
  13. H

    if i use mann-whitney,is it okay if i still use mean (not median) to compare 2 group?

    so in my minor thesis, i compare 2 groups (deaf and normal children; n1=n2=15) in their forward and backward digit span scores and word-list memory task (wlmt) scores (there are 4 scores: 1st, 2nd,and 3rd trial, and the mean scores of all three trial). in the normality tests, distribution is...
  14. S

    Fishy problem- which stat is appropriate? t-test or mann whitney

    Hello kind stats people, I'm in a bind! In my PhD I'm studying fertilisation success of 2 species of fish when they mate with each other. So how does mating success as a hybrid compare to that of the pure male. And just to complicate things I have them mating in different orders to see if...
  15. C

    Paired or unpaired test?

    Forum experts, I'm doing some environmental data anlalysis and I'm struggling with the correct statistics approach. I have data from 4 3-week studies where a number of parameters were collection both upwind and downwind of an emissions site. I have 1-min data that I have also averaged into...
  16. G

    Should I use Mann-Whitney?

    I have two independent, unpaired samples. Both distributions are non-Gaussian. One is plant data (n=95), the other is insect data (n=48). Both sets of data were sampled from the same location. Both sets of data are scores (i.e. nothing was measured). The scores are assigned to each species of...