welch

  1. B

    Post-hoc power analysis for a Welch ANOVA and also a Kruskal-Wallis test.

    I planned to analyse some data with several ANOVAs (I have many different dependent variables), but much of the data violates the ANOVA assumptions, so they require Welch's ANOVA or the non-parametric Kruskal-Wallis test instead. Using SPSS, I generated effect sizes (partial eta squared) and...
  2. L

    Welch ANOVA and covariates

    I had planned, because of lack of homogeneity of variance for some of my variables (homoscedasticity) to run a Welch's ANOVA and to use bootstrapping. I also have a number of covariates proposed for the (original) analysis. The Welch's ANOVA is only available for one-way ANOVA's on SPSS (no...
  3. S

    Welch's t test

    Short question; when do I use Welch's t-test? I don't quite get the "unequal variance"-thing. What does it mean that there is unequal variance and in what? If, for example, I test for gender inequality in education by to country groupings (ttest gender by 2 different countries), how do I then...
  4. gianmarco

    regular t-test VS Welch's t: white paper

    Hi, I came accross this interesting white paper. Here is the link. It deals with the topic of the assumptions of traditional t-test and of its comparison with the Welch's t. The pros and cons of each are evaluated. I found it in the site of Minitab program. Nonetheless, I think it can prove...
  5. B

    Dealing with missing cells in ANOVA

    I'm working on a project where I'm comparing sets of data from different measurement devices. I'm trying to do run several ANOVA tests in SPSS with the Welch test and Games-Howell post-hoc but am having a problem with my empty cells (they show up as " . "). The empty cells are missing pieces...