shapiro-wilk test

  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. G

    Sum of log normals not log normal; Monte Carlo Simulation

    The Problem is this: Let X1, X2 be two normaly distributed R.V. with equal Variance sigma, expectation 0 undCorrelation Rho. I Would like to: 1) simulate X1 and X2 jointly in excel; 2)simulate exp(X1) und exp(X2)jointly in excel ; 3) simulate exp(X1) + expe(X2); 4) show, that...
  3. L

    A non-parametric test for nomimal data made up from two independent variables

    I have been looking for a statistical test to run for some experimental data I have acquired. I have two groups (IV); Stress and Control mice. I have been looking at cell morphology. I performed a sholl analysis (which places concentric circles from the soma of the cell every 5 microns...
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    Justify the use of KS over Shapiro and Wilk normality test

    Hello there. I am testing my data distribution for normality using both Shapiro Wilk and Kolmogorov and Smirnov tests in SPSS. S&W reveals that the data is not normally distributed whereas K&S shows its approximately normally distributed. How can i justify the use of K&S over S&W in order to...
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    Getting same value (.000) of Sig. (or 'p') in Shapiro-Wilk Normality test

    Greetings to fellow talk stat members, I'm facing an issue with significance (or 'p') value in Shapiro-Wilk Normality test. Even after performing various data transformations (like log etc.), the p value is constantly getting displayed as .000, any help is appreciated. Thanks in advance.
  6. F

    different test for normality

    Hi, Can anybody give a brief description for different non-parametric tests of distributions (like normality)? what are differences between Kolmogorov-Smirnov, Lilifor and Shapiro-Walk tests for normality?
  7. P

    Testing multiple columns in R

    Morning all! Sorry, probably another newbie question. I have n columns of data, exported into 'R'. I want to test each column for normal distribution using Shapiro-Wilk' s test. I know how to do this for one column, using the filename$columnname argument. However, is there a shorter way...
  8. B

    2-way ANOVA Normality Requirements

    Greetings, My objective is to conduct a 2-way anova (equal sample sizes/246 samples) in R. After running the Shapiro-Wilk normality test on the residuals, I am getting a p value of =.0011 which signifies that the distributions are not normally distributed. However, the histogram of errors and...
  9. B

    RExcel command REval() only returns first value

    I'm dealing with large data sets that I'm updating regularly and need to see updating statistics in comparatively real time. I found the awesome RExcel package based on the rcon interface, and with the in-worksheet command REval() I can check any R stat instantly as I update it. Unfortunately...
  10. M

    why is my shapiro test for normality not normal?

    Could it be because I have 400 males and 500 females? my skewness, kurtosis histograms etc are all fine and my levenes test. I wanted to say in my report a possible why the shapiro said it wasnt normal.... could it be because of possible outliers or something? is there a way to look and...