# Questions tagged [ties]

Ties refer to equal values observed in the data. When multiple, ties can pose a problem for some methods of data analysis.

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### Wilcoxon Signed rank test for heavily tied paired data

We conducted an experiment to test the effect of a map annotated with the height of landscape features on participant's estimates of height relative to that recorded by a UAV. We asked them to record ...
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### How to simulate data with ties in R

I am using R to investigate the effect of tied values on rank-based correlation statistics I wish to simulate correlated bivariate standard normal data with some specified proportion of tied values (...
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1 vote
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### Chance of a tie for most goals in a set of 4 football matches

My statistics knowledge is basic at best but here goes: 4 football/soccer matches with expected goals of 2.6, 2.75, 2.4, 2.85 I'm interested in working out the probability of at least 2 of those games ...
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1 vote
2k views

### How to handle ties in pairwise wilcoxon rank-sum test?

I am willing run the wilcoxon rank sum test for different combination of variables, and using the base R code, I get a lot of warnings. The reason is that there are so many (about 30% of the whole ...
1 vote
2k views

### What methods can be used to overcome the tie-breaking when using majority voting in ensemble?

What methods can be used to overcome the tie-breaking when using majority voting in ensemble? I read that Weighted majority voting can help; however, it wasn't effective on the dataset I am using in ...
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1 vote
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### Use of Mann-Whitney w/ Ties

I am tracking the results of a test between a control group and 1 variant group. Each group contains (an unequal quantity of) users whose order count we're now tracking. The histogram is heavily ...
• 13
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### What happen if KNN has k=1 and there are 2 nearest classes with the same distance

What happen if KNN has k=1 and there are 2 nearest classes with the same distance? as fare as I know, If k is even number and have equal classes number it will random class for the answer. But what ...
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1 vote
6k views

### ties in Wilcoxon t test in R

I have a paired data with a small sample size of 19 subjects who gave different scores at time 1 ($T_1$) and time 2 ($T_2$). I'd like to conduct a Wilcoxon test using R, because my data are not normal....
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155 views

1k views

### Methods for handling ties in survival analysis

I am aware that there are different methods to deal with ties in survival analysis, which are based on alternating the partial likelihood used to estimate the beta parameters. I am working on a ...
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### Kendall tau for data with many ties

I am working on an an application that is part managed code and part unmanaged code. Because of the unmanaged code part, there was a requirement in the specifications that states that memory usage ...
303 views

### What are the accepted amount of tied ranks in your dataset when using the rank product statistic?

I'm currently trying to use the rank product statistic on very large datasets but I'm finding that a lot of the entries in my data end up receiving the same rank. To break these ties, I'm randomly ...
451 views

### Proving that the fit for a regression problem with tied input values can be obtained with reduced weighted least squares

This problem is from Elements of Statistical Learning, exercise 2.6 The problem states: Consider a regression problem with inputs $x_i$ and outputs $y_i$ and a parameterized model $f_\theta(x)$ to ...
1k views

### Stochastic gradient descent for neural networks with tied weights

For the neural network depicted below, I want to calculate the Error with respect to $w_{tied}$, which we get if we tie the weights $w_1$ and $w_4$ together. Tying the weights together would help to ...
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1 vote
501 views

### Wilcoxon Signed Rank test and reporting ties

In writing up results for a Wilcoxon Signed-Rank test, do you have to state if there were no ties in the data? Also, should the Z statistic be reported if the sample size is < 20 ? Thanks!
195 views

### Exact Null Distribution with Ties

I am interested in deriving exact null distributions for small-sample test statistics with non-trivial ties. Not fundamentally continuous variables that happen to have a few repeated values, but ...
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### Kendall’s tau-b version calculation steps with tied ranks

I am trying to calculate Kendall’s tau coefficient for example given by Scipy in python. It is for tied ranks with tau-b version. The tau should be -0.47140452079103173 but I get a different result. I ...
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840 views

### Slight inconsistency between the Kruskal-Wallis built-in R function and manual calculation

I'm confused by the following, and I haven't been able to dig up the answer elsewhere. I'm trying to learn R while doing some statistics, and, as an exercise, I try to double-check the results of ...
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### Tied rank correction formula vs fractional ranking in Spearman's Rank Correlation

I have found two ways to deal with ties when calculation Spearman's Rank Correlation. Calculate the ranks using fractional ranking, then calculate the Pearson's correlation of the ranks. Calculate ...
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2k views

### Autoencoders' gradient when using tied weights

In autoencoders when using tied weights, it was mentioned the gradient with respect to w is the sum of two weights. I didn't understand this, can someone elucidate this. it is mentioned here on slide ...
2k views

### Different methods for finding spearman's coefficient produce diff p-values depending on presence of tied values

I'm hoping someone can shed some light on the discrepancy between the p-values obtained from two different functions in R for conducting a spearman's test. The two tests produce the same p-values in ...
47k views

### "Ties should not be present" in one-sample Kolmgorov-Smirnov test in R

I am going to use the Kolmogorov-Smirnov test to test normality of MYDATA in R. This is an example of what I do ks.test(MYDATA,"pnorm",mean(MYDATA),sd(MYDATA)) ...
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### Understanding Kolmogorov-Smirnov test in R

I'm trying to understand the output of the Kolmogorov-Smirnov test function (two samples, two sided). Here is a simple test. ...
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### Autoencoder with tied weights: bias?

For some unsupervised learning problem, I need to train an autoencoder, so that I only have to store the encoder afterwards. However, I am not sure on how and if the bias weights can be tied. To make ...
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### Kruskal-Wallis: how to handle ties that might not be really ties?

I have data from a mass spectrometer that are precise to 6 decimal places and range from 0.1 to 10. However, some items cannot be measured by the mass spectrometer because they are "below the limit of ...
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2k views

I would like to compare the means of three groups using the Kruskal Wallis test in R. My data looks like this: ...
10k views

### Understanding warning message "Ties are present" in Kruskal-Wallis post hoc

I'm running post-hoc comparisons after a Kruskal-Wallis test. I'm using the PMCMR package. ...
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### Kolmogorov-Smirnov vs Mann-Whitney U When There Are Ties

I have a dataset consisting of rank data, some 100 cases and 2 groups. (The 2 groups contain about 1/3 and 2/3 of the cases.) I would like to test whether the two groups differ with respect to median ...
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### ks.test and ks.boot - exact p-values and ties

I am confused by the behaviour of ks.test (package stat) a) in the presence of ties and b) if one-sided while doing a two-sample test. Documentation: "Exact p-values are not available for the two-...
1 vote
1k views

### How to estimate Savage scores of tied ranks

I want to calculate the Top-Down Concordance coefficient that quantifies the agreement between two rankings by emphasizing more on the lowest rankings. The original paper is: R.L. Iman and W.J. ...
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### compare binary responses with ties

Suppose I am testing two drugs, I and II. The response profile is either I > II, I < II or I = II. I was trying to figure out if I is in fact better than II. One way I thought of was to throw out ...
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999 views

### Nelson-Aalen estimator and interval censoring/tied events

I just noticed that the Nelson-Aalen estimate of the cumulative hazard changes depends on the existence of tied events. As a toy example, consider a study with 3 patients. The patients die on day 1, 5,...
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### Dealing with ties, weights and voting in kNN

I am programming a kNN algorithm and would like to know the following: Tie-breaks: What happens if there is no clear winner in the majority voting? E.g. all k nearest neighbors are from different ...
2k views

### Mann-Whitney test with ties

I have two data sets with PDFs roughly like this: $$p(x) = \left\{ \begin{array}{lr} .75 & x = 0\\ \text{Lomax}(x) & x > 0 \end{array} \right.$$ i.e. it's ...
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### Is there an alternative to the Kolmogorov-Smirnov test for tied data with correction?

I've got a bunch of data from two samples (control and treated), each containing several thousand values which are to undergo significance testing in R. Theoretically, the values should be continuous, ...
• 275
41k views

### How does ties.method argument of R's rank function work?

I am using rank(a, ties.method="max") to rank a. But I am not quite sure what does ties.method="max" do. Can you please help?
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1 vote
1k views

### Cluster analysis with ties issue

When I perform cluster analysis in SAS, the SAS log sometimes return a warning something like this: ...
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### Ties in the data

Are there any "good" ways to eliminate the effects of ties in a data set for statistical analysis? For example, in finding the correlation between two series which has lots of ties? I would like to ...
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### Why are ties so difficult in nonparametric statistics?

My nonparametric text, Practical Nonparametric Statistics, often gives clean formulas for expectations, variances, test statistics, and the like, but includes the caveat that this only works if we ...
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### Is it wrong to jitter before performing Wilcoxon test?

I wrote a script tests the data using the wilcox.test, but when I got the results, all the p-values where equal to 1. I read in some websites that you could use ...
• 91
429 views

### What to do about ties in voting results?

Imagine a committee of people in charge of hiring a CEO. A committee member can vote "No hire" (+0), "Maybe"(+1), "Hire"(+2) for a potential CEO candidate. Each CEO is scored based on the votes, and ...
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13k views

### Survival analysis: continuous vs discrete time

I am confused about how to decide whether to treat time as continuous or discrete in survival analysis. Specifically, I want to use survival analysis to identify child- and household-level variables ...
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1 vote
2k views

### Does corr function in Matlab consider correction for tied ranks? [closed]

Does 'corr' function in Matlab consider correction for tied ranks while calculating Spearman correlation coefficient? Thanks.
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### Probability of Game Outcomes (with ties!)

Let's say I'm playing 10 "games". For each game, I know the probability of winning, the probability of tying, and the probability of losing. From these values, I can calculate the probability of ...