pairwise comparison

  1. N

    Kruskal-Wallis output problem

    Hi everyone, I have some troubles understanding some result of my Kruskal-Wallis test: I want to compare a variable across these 3 independent groups, and since its distribution is not normal, I run a non-parametric test. The test tells me to reject the null hypothesis (p=.000). The mean rank...
  2. J

    Pairwise Comparison Study Stats

    Hi, I'm looking to carry out a study which will involve a pairwise choice comparison. I am aiming to identify any patterns of preference by wild individuals (measured by abundance) when presented with four different types of refuge. I will be conducting it in the form of pairwise choice...
  3. S

    Best Method for Comparison of Bacterial Community Compositions

    Hi! I have curated 454 pyrosequencing data using Mothur. I have clustered reads from each sample into OTUs at a unique level. (Please see attached image of Excel spreadsheet) I would like to compare the bacterial communities within these samples in a pairwise manner (taking into...
  4. V

    Finding heterogeneity in simple data set (which day is the most different?)

    I have a data set with an amount of tests that were done by a group of people for each day over two weeks (no weekends). Basically, I need to know which day differs the most from others. Here is the data set: M T W TR F 48 43 42 40 50 47 49 42 46 51 38 44 47 53 52 41 46 47...
  5. J

    non parametric multiple pairwise comparisons - which correction is allowed?

    Hello all, I have a data set from plant experiments with only 4 replicates. data are numbers of mites after different treatments. Because the datasets are small they are not normally distributed, so I use non parametric tests: Wilcoxon. First I did a pairwise comparison, without corrections...
  6. I

    Pairwise Comparisons for Interaction Term, How to?

    Is there any way to perform pairwise comparisons for interaction terms? Linear Mixed Modeling runs pairwise comparisons for simple effects, but not the interaction terms. Thank you in advance!
  7. A

    can not figure out simple question, please help

    hi everyone! I have the following question: while running univariate GLM, I have encountered the situation when mean differences between groups are the same, but in one test they reach statistical significance, whereas in other not. Probably the reason is that in one case std. deviations are...
  8. L

    Needing a bit of help with sample sizes :)

    Hello, I'm new here so apologies if this is a simple question, I have tried a search online and here, but I'm am rather stuck. I am trying to do a sample size calculation for a multiple pairwise comparison. Within my study, participants are given three types of candy (A, B, and C)...
  9. B

    Bonferroni Correction

    I have been using SPSS for about four months. I am not a statistician. I continue to learn something new every minute that I am working with this program. I am looking at scores for achievement levels based on race. When I run the data, here are my steps: [LIST=1] Analyze multivariate...