All Questions
Tagged with nonparametric hypothesis-testing
308
questions
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Paired Non-parametric test with more than 3 groups but just two timepoints
I may not have found the right term to search for, so I am asking what might be a straightforward question:
Assume we have an experiment with paired non-normal distributed data, called "Pre" ...
1
vote
0
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35
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Combining Data from Multiple Participants for Statistical Analysis of a Facial Expression Memory Task
Context of the Query: I am working on a project involving a memory task for facial expressions, consisting of two phases:
Encoding Phase: In this phase, participants are exposed to 8 virtual ...
5
votes
3
answers
134
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Non-parametric one-sample mean test for a bounded variable (based on Chebyshev's inequality?)
The problem
I have $x_1, \ldots , x_n$ i.i.d. draws from r.v. $X$ such that $0 \leq X \leq 1$, but I can't make any other assumptions about the distribution.
I want to test the null hypothesis that $E(...
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3
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2
answers
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sample size in chi-squared test
The chi-square test of independence is a type of non-parametric test, but in cases of small sample sizes, the Fisher's exact test should be used instead. My understanding of non-parametric methods is ...
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22
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7
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Isn't it problematic to look at the data to decide to use a parametric vs. non-parametric test?
I've seen in some instances of people mentioning that using a parametric vs. non-parametric approach may be decided by looking at the data. For example this question: nonparametric vs. parametric
Isn'...
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How do I get from integral to computational formula of Cramér-von Mises statistic step by step?
My question is related to the calculus procedures behind Cramér-von Mises test.
How do I get from integral:
to computational formula:
of Cramér-von Mises statistic, step by step?
I understand the ...
0
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0
answers
22
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Statistical Significance Testing for Nested Cross-Validation in ML Experiment
I am currently working on an ML experiment where I use a nested 5-cross validation procedure and obtain a NDCG@10 scores for each test user. I am comparing 6 different ML algorithms and have data for ...
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Why does the Dunn's test in online calculator rejects the null hypothesis while my manual computations cannot reject it?
In my own manual calculations of the Dunn's Test in google sheet, using the formula from a YouTube video, I managed to calculate the same Test Statistic as the online calculator.
However, using the ...
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0
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25
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Appropriate Trend Analysis Test for Small Sample Size
Note: I have read Finding an appropriate trend test but unfortunately this post does not apply for me
Suppose I have a small sample of data for 2 numeric variables $T$ and $Y$ where $T$ represents ...
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Non parametric tests for 2 way anova and linear model? [duplicate]
My dissertation is due very soon and I have only just realised a large mistake in my work. I misread the normality test I used, which actually showed non normal data- but I still have homogeneity of ...
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How to compare peak location and tail length of two different distributions?
I have the distributions of the fraction of people in each income bracket in a town in 1990 and 2020. The total sample size is the same in both, and assume that the incomes have been adjusted to ...
1
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1
answer
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Deriving Sample version of Anderson Darling test statistic from the theoretical version
In literature, I have seen two types of Anderson-Darling test statistic. One is expressed as
$A_T^2 = n\int_{-\infty}^{\infty}\frac{(F_n(x)-F(x))^2}{F(x)(1-F(x))}dF(x)$ and the other is given by $A_s^...
- 115
2
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1
answer
80
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What non-parametric test for multivariate binary data should I use?
I have two different groups of participants ("g" and "b") answering the same set of questions. Group "g" answered questions in the same order. Group "b" ...
- 21
2
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2
answers
370
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How could Lilliefors use Monte Carlo if the estimand is not distribution-free?
Lilliefors test is a well-known statistical test for normality. Its idea is based on the Kolmogorov-Smirnov test, except the CDF is replaced by the CDF of the normal distribution with $\mu, \sigma^2$ ...
- 235
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103
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How to construct homogeneous subsets table for nonparametric tests?
Does post-hoc for friedman tests or nonparametric testshave like a homogeneous subset table from SPSS? Mean doesn't represent it well so I tried using median but my data was zero-inflated so the most ...
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3
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1
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131
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If I have a very small n for one group and a very large number of features, should I choose a parametric or a non-parametric test?
I have a dataset that contains human metabolite concetration in a fluid. One group has about 12 samples, while another only has 5. My question is if I can assume normality for this data and do ANOVA/t-...
1
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0
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23
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Appropriate tests and normalization approaches for highly non-normal data
I'm trying to ascertain whether a particular type of article, $T$, is associated with higher engagement scores in academic journals, and how substantial the effect size might be. I have raw data of ...
- 323
2
votes
2
answers
165
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Multiple regression on unpaired data (A~B+C)
I am not sure how to test one of my hypothesis from my data.
Basically, I have 3 behavioral measures A, B and C, and I want to test that A is a composite of B and C: A = B+C
However, for practical ...
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1
vote
1
answer
237
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In an A/B test, how can you check if assignment to the various buckets was truly random?
Trying to figure out how I can confirm that my A/B Test assignment is truly random. I know the runs test is used to test for randomness.
Is it possible to use the runs test to check if my A/B Test ...
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0
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37
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Relation between the sample size with the powers of Kolmogorov Smirnov, Cramer Von Mises and Anderson Darling?
I want to know the mathematical relation between the sample size with the powers of 1. Kolmogorov Smirnov, 2. Cramer Von Mises, and 3. Anderson Darling.
I have seen many posts and other websites ...
1
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1
answer
106
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Statistical test for differences where output is -1, 0, 1?
He's the situation, say we have n data points. There are two treatments A and B. If treatment A was better than treatment B we give a score of 1, in the opposite case we give a -1, and if there is ...
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2
votes
2
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115
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Distribution and variable analysis
I am doing a statistical test (program used is SPSS). On the basis of distribution and sample size, I have to chose the correct variable analysis. I also have to justify every decision. I have two ...
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2
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1
answer
61
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How to Replicate result that probabilities in included table are different 7 times?
Question: In the table at the bottom of this question, the total number of times that $\hat{P}(x;z) > \hat{P}_y(x;z) $ and $\hat{P}(y;z)>\hat{P}_x(y;z)$ is 7.
Can someone please replicate this ...
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0
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44
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Which Non-Parametric Test should I use?
I want to make sure I am choosing the right statistical test.
I am working with 7 semesters of exams scores for a particular course.
Each semester the course ran with many sections. However, the ...
- 11
0
votes
1
answer
68
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Bootstrap P-value and confidence intervals with more than two samples
I have been trying to find a simple way to use the bootstrap for a hypothesis test that involves more than two samples. The motivation for using the bootstrap is for the usual reasons: the test ...
1
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0
answers
64
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I'm having trouble choosing between Wilcoxon matched pairs test and McNemar test for a data set
I have a data set on a large group of long-term stroke survivors. I need to determine whether there is a difference in ability (on a scale of 1-10) between their left and right arms. The ordinal data ...
4
votes
1
answer
77
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Which statistical method to use to compare reinforced colour and speed of learning?
I'm working on my master's thesis where I'm trying to determine whether sea turtles are capable of discriminating between colour. One subcategory I'm looking into is seeing whether the speed they ...
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175
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0
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1
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485
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which non parametric test is best for ordinal data?
I want to to do the test where i have to check if first column which is income, and 1 shows < 500, 2 = 1000, 3 = 2000 income values from the data, and which the other column which is a dependent ...
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229
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How to interpret results from the data if Levene's test is violated?
I'm doing ANCOVA analysis. So, the assumption of Levene's test is violated which means I have to run a non-parametric test. Does that mean I can't interpret other results that I obtained from the data ...
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2
votes
0
answers
144
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One sample Wilcoxon Rank-Sum Test to compare percentiles
I have 10th, 25th, 50th, 75th and 90th percentiles of a population which is NOT normally distributed. On the other hand, I have a sample from that population and I want to test if its percentiles are ...
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2
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1
answer
56
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Can you help me determine if these two groups are statistically different?
I have two groups, A & B. Let's say A are the users who wrote a review for place A, and B for place B.
For each user $u$ I have recorded his total number of reviews $r_u$. Since we're talking ...
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0
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31
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What type of test should be used in this case?
I have a pandas data frame with a target variable, which is binary (classes progressive / non-progressive), that I want to ...
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6
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1
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163
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Geyer: nonparametric bootstrap hypothesis tests typically have no power. Why?
I came across this page and was surprised and confused by the following:
A naive person attempting to do a bootstrap test just calculates a P-value as something like
mean(tstat.star > tstat.hat)
...
- 201
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0
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17
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Non-parametric test for separating samples from two populations
I have samples $\mathcal{Z} = \{Z_1,\ldots,Z_n\}$. These samples either come from the unknown distribution $\mathcal{D}_1$ or $\mathcal{D}_2$. (Note: I can't make any assumptions about these ...
1
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1
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689
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Small sample size: Permutation test or Wilcoxon test?
What do you think about using a permutation test each time the sample size is too small to meet the the assumptions of normality and homogeneity of variance etc ? Why do we use a non parametric ...
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2
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1
answer
571
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Which non-parametric test should I use to compare 2 independent groups when i have several ties (Wilcoxon not good for this weird sample)?
I'm doing an analysis of a master's student in which I need to compare a continuous numerical variable between two groups. The samples are independent and each group contains only three observations ...
1
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4
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131
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Business use cases for Wilcoxon signed-rank test
The Wilcoxon signed-rank test is generally used for non-parametric data (i.e. not normally distributed). When the sample gets large, the data will be approximately normally distributed. Therefore ...
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0
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27
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How can I test for a significant difference here?
I would simply like to compare the frequency of two variables that come from the same sample. The variable longgain has the value 1 if a gain in the portfolio of an investor is held for longer than ...
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0
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87
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Which statistical Test should I use/ Comparing 2 groups
I am new to statistics, can someone guide me regarding the test I should use to compare the foot dimensions of 9 subjects to footwear dimensions (we have 2 footwear brands).
So, to simplify, I have ...
1
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2
answers
82
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Are t-tests good choices here?
I would like to test if two groups of participants (dark-eyed and light-eyed individuals) respond to a drug differently over time. The hypothesis is that the drug reaches its peak effects sooner but ...
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Is log-rank parametric or non-parametric test, and why?
How is the log-rank test a "non-parametric test" according to wikipedia.org if one has to specify the parametric survival model for this test?
We may run log-rank under the assumption of ...
user318514
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Sample size planning method differs from analysis method
I have seen some articles using one method for sample size estimation(two sample comparison for means or proportions) and subsequently using regression analysis/non parametric methods.
If I have a ...
- 1,445
1
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1
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60
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alternative to ANOVA or simplifying approximations for multi-factor,, batch design with binomial data (advanced beginner)
this is my first post. I did already read various didactic materials and related posts here, but still had trouble figuring this one out. Sorry this is so long but I am trying to be as specific as ...
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2
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1
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240
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Wilcoxon Rank Sum test - appropriate to compare frequency of events between two sources?
I have some data on the frequency that a particular claim is referenced by two distinct types of sources. The first is traditional news media, and the second source are conspiracy theory sites. I want ...
- 323
1
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0
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30
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Seasonality test for poissonian counts
I have a count $N_i$ of rare evevents for each season, where $i$ identifies the season. The counts' rates are not high enough to justify a normal distribution aproximation of the poissonian.
I want to ...
- 11
0
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0
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50
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How to validate the effect of the type of Task on participants' performance using count data
We conducted a user testing with two groups of participants (Group_A, Group_B).
Group_A performed Task_A (a writing) under Condition_A.
Group_B performed Task_B (a writing) under Condition_B.
Group_A ...
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1
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1
answer
585
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Welch's t test vs Mann-Whitney for very unequal groups
I have two vastly unequal groups (n1=18 and n2=400), and want to test mean differences between the groups for some 700 parameters (more specifically, RNA expression levels for 700 genes).
While I ...
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1
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1
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105
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Help finding the right test
I am running an experiment and now it is time to do some analysis, but I am having a hard time figuring out the right way to analyze my data. I have a number of questions, but first let me give you ...
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0
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45
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Similarity measures for Probability Mass Functions
I am trying to predict whether two sets of papers are written by the same author by looking at the distribution of papers over the years (number of papers published in a given year). Suppose we have ...
