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Homework Help: Question about repeated measures Anova and multiple regression

  1. Dec 15, 2011 #1
    This is for my coursework. I have two problems. The first one.
    1. The problem statement, all variables and given/known data

    I have two time messures. Before and after a scheme was introduced.I have to answer a question if it made a statistically significant difference or not. And also as it was introduced in 3 places I need to know if it worked equally well in all of them.

    Two time meassures are on the interval scale, place is a categorical variable place 1, place 2 and place 3.
    The major problem is that data is not normally distributed (and it is impossible to fix that, I tried various data transformations), so my question is which non-parametric equivalent test should I use?

    2. Relevant equations

    To be honest I can't decide if it is a one way repeated measures anova or mixed factors repeated measures anova as I am still new at this topic. I just keep changing my mind and performing these tests again and again (parametric versions, although I am aware I should go with non-parametric test)

    3. The attempt at a solution
    As I mentioned before I tried tranforming the data in order to make the distribution normal but I have never (so far ) seen anything so far from the normal distribution pattern and nothing is working.
    Another question:

    1. The problem statement, all variables and given/known data

    I have two IV and 1 DV (all are interval) and I need to build a multiple regression model to be able to predict DV from these two IVs . However, residuals are not normally distributed also there is heteroscedascity.

    How can I fix this, should I use general linear model (via SPSS) to build my equation instead? How? So far I only dealt with data which met the assumptions.
    2. Relevant equations
    I need to use multiple regression, also to find which of the two is better predictor
    3. The attempt at a solution
    I tried data transformations but how do I know which variable to transform and which transformation to use? Also I tried using general linear model but I am not sure if that is aprropriate.

    I didn't give much details because I don't think I can do that. I hope the information I provided is enough to understand the types of problems I am facing.

    Thank you.
    1. The problem statement, all variables and given/known data

    2. Relevant equations

    3. The attempt at a solution
  2. jcsd
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