All Questions
Tagged with nonparametric normality-assumption
52
questions
1
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0
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106
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Bounds for hypothesis testing with non-normal distributions
After doing randomized experiment with two variants (AB tests), I want to do hypothesis testing without the normal distribution assumption to compare their means. Since the samples sizes are different,...
1
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0
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287
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Testing for normality with small sample sizes in order to use t-test [duplicate]
I run into a conundrum when determining whether a small sample is appropriate for a t-test. I know that if I meet the assumptions, a t-test produces approximately correct inference with any sample ...
- 497
1
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2
answers
3k
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Multiple comparisons for not normal and heterogeneous data
I have a data set that has 3 groups and a single variable. Under normal circumstances, a one-way ANOVA would be used for comparisons between my three groups. HOWEVER I ran a Shapiro-Wilk test for ...
0
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0
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50
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Parametric v Non-Parametric?
I've recently began doing some data analysis for a sample of around 5800 respondents who are categorised into four different groups in relation to different levels of psychological connection in a ...
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1
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0
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144
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Coverage of confidence interval of non-normal distribution
I know that when a sample is non-normally distributed, I need to use non-parametric alternatives, as when the assumptions of parametric methods are violated, its coverage will decrease.
Let's say ...
- 1,041
0
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1
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584
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What is exactly the non-normality requisite for nonparametric tests? [duplicate]
As the title says, what is exactly what is being tested before deciding to use a non-parametric alternative test (as Kruskal-Wallis for ANOVA, or Mann-Whitney's U for student's t)?
Most sources are ...
- 1,472
0
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1
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213
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Normality Tests in samples with outliers
I'm making a code in R that contains some parametric and non-parametric tests, like ANOVA and Kruskal-Wallis.
To know if I should use one or another I check the "normality" of the test sample. My ...
3
votes
3
answers
2k
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Tests of normality - qq and Shapiro-Wilk
I am new to the world of stats ...
My data had a log normal distribution, so transformed by log to get it nearer normal distribution. This is real-world data.
From here I want to establish if my data ...
6
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2
answers
3k
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Wilcoxon Test - non normality, non equal variances, sample size not the same
I know there are already a lot of posts out there, but I couldn't find this exact combination in any of them.
Comparing two samples (Prices associated with men and with women), but I have neither the ...
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2
votes
1
answer
382
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Meta analysis Cliff's delta
Cliff's delta is an effect size typically recommended whenever the normality and homogeneity assumption do not hold---and thus, Cohen's d cannot be used.
However, I cannot see any reference ...
- 157
2
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1
answer
5k
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Paired t-test of a non-normal data with sample size 66
I have a paired data with n=66. I understand that normality condition of differences data should be met to conduct a paired t-test. However, from the histogram, it doesn't appear so normal. The p-...
- 135
3
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1
answer
5k
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Two-Way Non-Parametric Test for Non-normal Data?
I have an unbalanced design with two factors, gender and site. I'm trying to test for differences in a size variable. Levene's test reveals that the data has equal variances. However, log transformed ...
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3
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2
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2k
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Theil-Sen estimator assumptions
I found by accident the nonparametric Theil-Sen Estimator as a replacement for standard OLS linear Regression. How well does it perform with autocorrelated data, non-normal residuals and ...
- 69
1
vote
1
answer
226
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Should I use non-parametric tests?
I am a teacher working on a simple research with the aim of studying whether the set of lesson designs I created can improve student performance. I have two groups with 15 students each. I divided ...
0
votes
1
answer
359
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Do I need to check for normality in a one-way test (in R)?
http://www.sthda.com/english/wiki/one-way-anova-test-in-r
Here it says when the LeveneTest has small p-value we can use the alternative one
...
J.Doe