Questions tagged [shapiro-wilk-test]
The shapiro-wilk-test tag has no usage guidance.
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How to compare three groups of patients if one group is normally distributed but the other two are not?
Retrospective study involving three groups of patients. Group 1 are patient's diagnosed with sepsis. Group 2 are patient's diagnosed with a localized infection. Group 3 are "healthy" ...
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Ambiguity between Statistic Normality Test vs Visual Normality Check
I'm learning some basic EDA using the Boston housing price dataset and I want to filter out outliers in the feature columns. To do that I first wanted to understand what distribution each of my ...
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My professor insists that this data is normally distributed but I cannot work out how that can be!
I have a data set on deforestation and the impact that the distance from a road has on deforestation. For the assignment, I need to assess the correlation between these two variables. In class, my ...
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Heteroscedasticity in linear mixed effects models (lmer)
I am computing the following model in R, using lme4::lmer:
m3 = lmer(e ~ (X*Y*Z) + (1|ID/R), data = data_transform)
e is a continuous variable. X, Y, and Z are ...
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Wilcoxon's Signed-Rank Test in the context of 2 algorithms and 1 domain
I'm trying to understand whether my analysis for a problem is in the right direction.
I have 2 algorithms (3d object detectors) that I've applied to the same dataset to obtain TP, FP and FN's for each ...
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Can I violate assumptions of normality for categorical linear regression models?
I'm using packages included in this R/rStudio tutorial to set up some linear regression models comparing a continuous dependent variable (eccentricity) to three categorical variables (year, bird ...
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About the normality question with four conditions
I am encountering difficulties in determining the normality of data and distinguishing whether the data I have collected is parametric or non-parametric.
I have gathered data using a 7-point Likert ...
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When to use Pearson's test and when to use Spearman's test?
I want to do a correlation analysis on a dataset of 28 samples.
I want to correlate the age with the size of a reflex response.
But I don't understand whether I should use Pearson's or Spearman's test....
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Do I need to use a factor for the ANOVA? [closed]
The problem:
A psychologist is interested in short-term working memory under (1) sleep deprivation, (2) a strong dose of caffeine, (3) following 8 hours sleep. They conduct a between subjects design. ...
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How to test for normality on paired samples between two treatments when the number of observations per treatment is unequal?
I have mice which need to poke a device to receive food across a one hour period. The device records the number of pokes and poke_time which is the duration that the mouse remained in the poke hole. ...
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Can I assume normal distribution?
I have calculated daily price returns of Bitcoin and plotted this data in the following way:
x-axis: returns in %
y-axis: count
I assumed the data had a normal distribution to calculate the
$$\rm ...
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Can I remove a single data point if it is changing drastically a Shapiro Wilk test?
I'm conducting a hyphotesis test to compare the mean of two independent samples.
To do so, I need to check normality of both samples.
I have two samples of size 20.
A single data point, on both ...
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How to determine normalcy for a one group pre-test post-test? [duplicate]
My study is a retrospective one group pre-test post-test on multiple variables. Not every patient in the study had scores for all of the variables, so as long as a patient had both a pretest and a ...
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Are there differences for the Shapiro tests in Python and R?
I am aiming to reproduce the issue (using Python) described in the answer here Is normality testing 'essentially useless'?
It states that the assumption of normality is more likely to be ...
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Why does checking normality of residuals give a different result than checking bivariate normality of the two variables?
I am checking the conditions for hypothesis testing a Pearson correlation as significant or not, and also checking the residuals normality conditions for OLS. Why are the following methods giving ...
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