non-parametric anova

  1. L

    Testing normality of distribution: Shapiro-Wilk's test/Levene's test?

    I have data from an experiment with 5 conditions. The goal is to compare the impact of treatment on dependent variables between the conditions. To determine whether to use ANOVA or non-parametric equivalents, I conducted Shapiro-Wilk's test. It shows that the data is not normally distributed, so...
  2. S

    [R] Non-parametric test to multi factorial ANOVA

    Hi, I've spent hours searching online (by "non parametric factorial ANOVA"), reading in books (Zar's "Biostatistical analysis") and manuals (R), but I can't find any clear solution, so I'll bite the bullet and I whine to you. First, sorry for my English and my lack of Statistical knowledge...
  3. K

    Planned contrasts in Friedman's ANOVA

    Is it possible to investigate planned contrasts in Friedman's ANOVA or is it only possible to investigate pairwise comparisons? Thank you for your help!
  4. L

    I need to test within and between factors at the same time. Which test should I use?

    Hi everyone, I'm trying to analyze the results of my Master Thesis with SPSS. I've 3 experimental conditions (factor: Group) and every subject in each condition has 2 expressions (factor: Hemisphere). I want to test the effects of these 2 factors on my dependent variable A. What I would like...
  5. P

    Kruskal Wallis/Dunn's test issue

    Apologies, I cannot find an answer to this on these boards... Anyway, first post... I have been asked to look at some stats by a colleague, and have hit a brick wall (at least in my head). The lab involves up to 30 germinating seeds under a treatments of nutrient, all other conditions...
  6. R

    Implementing non-parametric version of 2x2 Repeated Measures ANOVA in R

    Hi, I have a 2x2 repeated measures design (i.e. 1 group of participants provide data for all 4 conditions in a fully factorial counterbalanced design [so there is no time factor to worry about]). The data is non-normal so I need to use a non-parametric equivalent of the 2x2 factorial ANOVA...
  7. I

    Kruskall-Wallis: what can we do if not significant?

    Hi all, I have a general question regarding Kruskall-Wallis test: When Kruskall-Wallis test DOES NOT yield significant results, can we still run Mann-Whitney tests with specific pairs of the conditions? If those pairs are significant, can we consider those results? Thanks a lot in...
  8. R

    ANCOVA when variances are not equal?

    I am currently writing a 4th year freshwater biology report analysing data collected on the length and weight of fish from 2 sites, collected over 3 years. We need run an ANCOVA checking Weight v Length/Site(SPSS, weight=dependent, site=factor, length=covariante). After checking...
  9. C

    A non-parametric ANOVA for nominal data

    Hi, I have a research project that has two groups, I'm trying to analyse people's response to an open ended question that I have coded according to five themes. So, when I input the data into SPSS, each row has what group they are in and the theme (1-5) that they have. Would anyone know...