Questions tagged [paired-data]
Paired data arise when an experimental or observational study design deliberately samples two units as a dyad to form a basis of comparison. Use this tag for any question about paired data or their analysis.
581
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How do two of my Wilcoxon signed rank tests have the same p-values?
I'm running a statistical analysis where I'm comparing land surface temperature in matched equal sized areas (project areas and control areas) of different cities. In each city, I do it for two ...
2
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0answers
32 views
How to do a comparison between A or B between ten samples
I am planning a research which will go as follows,
There will be ten participants and each will perform the same exercise. However they will be wearing the variant A or variant B of the garment we ...
2
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0answers
13 views
Paired non-parametric test for a difference in variance
I have $N = 391$ paired data points $\mathbf a = a_1, \ldots a_N$ and $\mathbf b = b_1, \ldots b_N$.
Both $\mathbf a$ and $\mathbf b$ are approximately normally distributed with a mean of zero.
I ...
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0answers
25 views
Another solution than McNemar test for bilateral asymmetry on binary data?
Let's say I studied the shoulders of 10 individuals, and I scored the presence/absence of a criteria (ex: arthrosis, presence=0;absence=1) on the left side and the right side.
I need to test the ...
0
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1answer
23 views
Paired t-test between different algorithms: Properties of paired t-test
Suppose,
Accuracies are:
Algorithm 1: 87%
Algorithm 2: 86%
Algorithm 3: 88%
Paired t-test value between Algorithm 1 and Algorithm 3 is p = 0.44
Paired t-test value between Algorithm 2 and ...
0
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1answer
28 views
How to test if two time series are the same (aka same distributions, or no variation in their difference)? [on hold]
I have many different time series. One time series is the control period. Many other samples are the test series.
I want to see if each test sample is different than the control period. The best way ...
2
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0answers
13 views
Paired sample: Two-tailed and one-tailed
In the book: "Essentials of Statistics for Business & Economics", the part about matched sample t-test, I see that it uses the two-tailed t-stat. However, instead of stating the null and alternate ...
0
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0answers
14 views
Paired experiment with trinomial response - Analysis help!
I'm looking to analyze data (in SAS) from a trial investigating the effect of a particular protective padding on preventing skin irritation at multiple body locations among spinal surgery patients.
(...
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1answer
15 views
Dissimilarity or distance metrics between pairs of values
I have cubes (objects) in which their volume was manually calculated (let's call this method the "manual method". Assume that the volume measures obtained by this method are considered the "true" ...
0
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1answer
29 views
Planned comparisons with ridge regression
I have a data set that consists of 1 response variables (e.g., response time) and 20-30 predictors variables with a mixture of categorical and continuous data. I code the categorical data into dummy ...
0
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0answers
13 views
Quantifying error with paired measurements from multiple conditions
I have a set paired measurements (continuous values) obtained using different sample types and different methods. I.e., for each subject, I have measurements for samples A and B each on device 1 and 2 ...
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0answers
28 views
Paired sample, quasi-matched controls, and a covariate - ANCOVAs in R?
I have been going around in circles on this question for a while, so figured I'd resort to the expertise on stackexchange.
My data: I have performance on a multitude of functional tests taken at 2 ...
1
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1answer
23 views
How to adjust a confounder in pre-post analyis
I have a paired-dataset of pre and post-surgery measurements of certain biomarkers. I have done a paired t-test to find if there is a difference in the levels of a biomarker, say x1, before and after ...
0
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1answer
14 views
Mix of paired and independent data analysis [duplicate]
Is there any data analysis that can be performed on both paired and independent data? For example, we have scores on a questionnaire for individuals who were exposed and not exposed (control) to a ...
2
votes
1answer
27 views
Would a paired or unpaired t-test be more suitable for this dataset?
I have data that measures the temperature of flowers and leaves on different plant species. These are the comparisons I am trying to make:
Comparing the flower and leaf of the same plant at the same ...
1
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1answer
40 views
post hoc pairwise comparison
I have a model testing whether the modifications to my texts (fixed factor: Modified) affect several measures (for example IA_FIXATION_COUNT). The Texts used in my experiments are 8, and when i want ...
0
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0answers
10 views
Samle size calculation for paired comparative diagnostic accuracy study
I would like to estimate an appropriate sample size for a medical imaging study.
I prefer to use R.
A standard thest testS will be compared to a modified standard ...
1
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1answer
28 views
Comparing survey data to passively measured data
Basic Situation:
I have quite a large sample of around 10k people.
In that sample I have two values for each person: a passively measured value of an amount of time, as well as their estimation of ...
1
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1answer
36 views
paired test VS unpaired test
I have a set of paired measurements which were collected before and after some trigger for a set of users. Users can react differently to trigger, i.e for some measurements before trigger are larger ...
0
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2answers
13 views
Paired / unpaired data - age groups within company
I have (I think) a relatively basic question concerning paired / unpaired data.
I want to compare the mean number of employees in the same company in the same year across two age groups (under 50 ...
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0answers
13 views
Is it reasonable to do a test of marginal homogenity (mcnemar-bowker) when some combinations of the cells cannot possibly occur?
I have some patients that have none, mild and moderate form of a disease monitored at baseline and at 6-months. I would like to do the mcNemar-bowker test to see whether the drug given to everyone has ...
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0answers
27 views
What statistical test could I use to compare categories of two data sets (for enrichment) with hugely different sample size?
I have some biological variant effect prediction data. This data can be split into categories based on the biological effect each variant has. I've turned this into two data sets: One is the "full" ...
2
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2answers
46 views
Weibull Stats for Testing Significance of Ultimate Strength in Mechanical Failure
First, I'll start with some background that may explain the ignorance that will likely be encountered in the remainder of the post. I am an archaeologist attempting to study the flexural strength of ...
0
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0answers
30 views
Comparison of multiple variables in paired data
I'm trying to visualize/analyze some data but unfortunately I don't know which would be the right way to approach my problem. My apologies if the question appears somewhat vague: the scenario ...
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0answers
15 views
Why several studies change logical paired/unpaired assumption from omnibus to post-hoc?
There are several studies of highly-referenced researchers where a paired post-hoc test (e.g. Wilcoxon signed-rank) follows the omnibus unpaired test (e.g. Kruskal-Wallis):
From Huang et. al "THE ...
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17 views
How to calculate the significance of slope and y-intercept using a permutation test of pairwise fst x distance
I have two variables,
1. scaled pairwise Fst (measure of genetic differentiation between two sites)
2. river kilometers between the two sites.
The values are not independent (all of the sites are ...
0
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0answers
13 views
Can I use UNPAIRED post-hoc analysis for PAIRED omnibus testing?
If I have a omnibus statistical test with unpaired assumption (e.g.Kruskall-Wallis), could I ever use the opposite (paired) post-hoc analysis? (e.g. Wilcoxon signed-rank for post-hoc analysis of ...
2
votes
1answer
65 views
Weighted Pairwise Comparison With Table-like Heterogeneous Data - Is Bradley-Terry Model The Right Choice?
I came across this library Choix. I want to do Pairwise Comparison on data that looks like this to output a ranking from best to worst.
Let's call this X:
...
0
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0answers
52 views
NcNemar's test for 1:2 matched data
Does anyone use McNemar's test for fractional values after 1-to-2 propensity score matching? How correct would it be?
For instance, let me have 0-1 outcomes and the following matched observations (...
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0answers
27 views
Pairwise comparisons pre test post follow up
I have to complete my dissertation in a couple of days. I am proposing a RCT with two independent variables: treatment( group 1 : avatar cognitive therapy , group 2: CT) and time(pre-test, post-test ...
0
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1answer
22 views
How to plot paired data that has small deviations?
I am showing that applying a certain method leads to improved performance on a machine learning problem, and that this effect is consistent across different datasets (in this case, datasets collected ...
0
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1answer
24 views
Independent or matched groups?
A very beginner level question here: I'm trying to see whether there is a difference in how students assess the usefulness of 5 possible courses to be added to their curriculum. Each student was asked ...
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0answers
32 views
Bayes factors in R for correlated proportions (such as a “Bayesian McNemar's test”)
Is there any way to get Bayes factors in R for correlated proportions (i.e., paired sample)?
For example, the same group of 90 people is measured with one technique, then with another; once there are ...
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0answers
3 views
Comparing which histogram has overall low cost
Let's say there are two histograms which basically is constructed from array of numbers which is measured by, repeatedly performing a task by two different methods and individual numbers are time ...
2
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3answers
233 views
Paired t-test means that the variances of the 2 samples are the same?
Do paired samples imply that they have the same variance?
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0answers
11 views
Scale invariant comparisons of two sets of vectors
I am dealing with the following problem.
Let A and B represent two sets of real-valued vectors. The vectors are of the same dimension, yet the sets contain different number of vectors.
I am looking ...
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0answers
16 views
Potential problem in using paired t-test or Wilcoxon if the two samples consist of multiple draws from same group?
I have an experiment that works loosely works as follows:
There are ten subjects in each treatment. There are two treatments, A and B. Each treatment has 8 rounds. In each round, each subject is ...
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0answers
16 views
Proper analysis procedure of paired rate comparisons - ratio or difference?
I have a set of population counts where each row represents a different region, and variables show overall counts and counts/percentages within specific groups/criteria. I am interested in the cross-...
3
votes
1answer
52 views
Is my interpretation for Wilcoxon Signed Rank test correct?
I ran a wilcoxon signed rank test on paired samples where the outcome variable was a test score. The samples were paired by as siblings (younger and older sibling). I have a problem interpreting the ...
0
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1answer
39 views
How does Normal approximation work when ties exist for Wilcoxon Signed rank test?
I ran wilcox.test() in R (outcome variable was a test score and the data was paired samples) and got a warning message saying that it cannot generate a p-value for tied values. I saw the R document ...
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0answers
28 views
Compare variables with zeta-score
Assume the calculation of a physical quantity $x$ from a given formula i.e. $$x=\dfrac{a*b}{c}$$ where $a, b$ and $c$ are experimental observables, therefore $x$ is a quantity derived from ...
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0answers
53 views
Statistical test for dependent data- comparing groups of pairs
I have a question about statistical tests for dependent data. This will sound a bit strange/extremely naive but pls bear with me- here is my problem formulation:
I have 500 individuals, and I'm ...
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0answers
25 views
how to report paired comparisons in linear basis function model?
I am struggling with correctly reporting the results of a linear (mixed) basis function model I ran. The model is specified in R as
...
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0answers
47 views
Using a paired t-test on panel data
I am working with a data set containing approximately 100 students who have all been tested before and after and intervention. I am now going to test whether the intervention has had any impact on the ...
2
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1answer
165 views
Paired or unpaired t-test and Wilcoxon signed rank test?
I am having a conceptual problem, of not being able to grasp whether my data is paired or unpaired. I have to test for the mean and median differences between two sets of data: SBP and GICS (see ...
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0answers
41 views
Linear model for paired data [closed]
We have 100 subjects of varying and known age and sex with two strongly related dependent variables (X, Z) measured with two methods (A and B). Method B is known and expected to show more reduced ...
0
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1answer
26 views
Logistic regression: Sample size for emmeans comparisons
I conducted a logistic regression with a 3-levels categorical predictor in SPSS using the GENLIN procedure. As I am interested in the pairwise comparisons between all three predictor levels, I used ...
0
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1answer
44 views
One tailed paired t-test
Ok, this might be an obvious question but it's had me stumped.
Let's say we're doing a test to see the improvement on test scores before and after some process.
We could state the hypothesis as:
H0:...
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0answers
16 views
Wilcoxon rank signed test, paired or non-paired test?
I have been trying to figure out, whether or not I should use a paired or a non-paired test. My question comes from the fact, that I am trying to get the pseudo median, in order to say that SBP is [x] ...
0
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0answers
27 views
Comparison of paired count data between two treatment periods with different length of follow-up
I am currently using SAS 9.4 to carry out a retrospective analysis of patients who switched from drug A to drug B. I am interested in assessing the hospitalization counts before and after switch to ...
