methods for comparison when the measurements to be compared are used each on the same subjects, so for each subject we get a pair of measurements.

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11 views

testing multiple paired ordinal measures

Please give me advice on a robust way to evaluate multiple ordinal measures. I have a group of n subjects who have a treatment for spasticity (abnormal muscle stiffness). A measure of spasticity is ...
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1answer
19 views

Weighted, Paired-Sample T-test? in R [closed]

In R you can run a paired t-test (e.g. t.test(x, y, paired=TRUE)) as well as a weighted t-test (e.g. ...
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1answer
24 views

Pairwise comparison with Bradley-Terry

I am performing a pairwise comparison test for the perceived weight of objects. I want to estimate the difference between each pair, say, A - B. I suspect that the underlying distributions of A, and ...
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0answers
23 views

Paired or non-paired data? comparing two sets of scores from same individuals

I have data from four companies, W, X, Y and Z. For each company, three groups of 5 individuals (15 individuals total) take part in a test. Every individual takes two tests, test A and test B, with A ...
5
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1answer
112 views

Can a paired t-test test if the difference between two means is less than a specific value?

In paired t-tests we test if the difference in means if 0 (or another value). I'm wondering if it's possible to instead test if the difference is less than x?
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2answers
22 views

Comparing mean test scores (different tests, same group)

I have the following problem: There is 1 group of students (student 1, student 2, ..., student n) This group of students takes several tests (math, French, Biology) - all scored as percentages ...
4
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1answer
41 views

I have 12 items to get into a single rank order. Can I get this from having a few hundred people see a set of 10 of the possible pairs of items?

I attempted to run a study where people had to rank order 12 statements from best to worst. However, it was extremely messy and difficult for people to rank that many items. Now, my professor and I ...
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1answer
25 views

Matched data: Paired t-test vs. indpendent

Suppose I have a group(X) of people receiving a treatment for high blood pressure. Suppose I match these people to controls(Y) who have high blood pressure but who are not receiving any treatment. I ...
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2answers
58 views

What statistical test is appropriate for paired data where the same subjects are tested at multiple times?

In the test in question, we have data [measurements of discomfort] for the same subjects with different virtual reality experiences. We took multiple measurements of discomfort over the course of the ...
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4 views

Compute average pairwise correlation Y(X1) vs Y (X2) within many nonoverlapping intervals of variable X

I am pretty sure someone already solved this problem and shared the code. Could you please help to find it? I need to calculate the pairwise correlation for the values of a discrete function Y(X) ...
3
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0answers
23 views

Is the Wilcoxon Rank-sum test the best option with many near 0 values >0?

I have a two very large datasets. They look something like this, but with a few thousand rows. They are the total number of tyrosines in a short DNA sequence with a length of up to 5. A would precede ...
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34 views

Is this simple paired-sample permutation test valid?

I have about 10 pairs of scores, $(x_1, y_1),~ ...,~(x_{10}, y_{10})$, with all $x_i$ and $y_i$ being between 0.0 and 1.0. I'm interested in testing whether the mean difference over pairs is ...
3
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63 views

Paired comparison of instruments using different measurement samples

I have instruments A, B, C and D - I'm in search of the best one. The problem: For illustrative purposes, let's use an example of evaluating the best among the instruments measuring difference in ...
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1answer
92 views

Looking for the right statistical test. - Wilcoxon signed-rank test?

I'd like to test if three data sets are statistically similar, but I'm not sure which test is the right one (because the examples on the internet are all very simple). I start with a list of values (1 ...
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0answers
12 views

Best possible statistical approach to compare n pair of variables along a set of genomic intervals

I am dealing a bioinformatics problem and need help in approaching it in the right direction. I have a set of variables that represent different kinds of genomic data and are real valued. I am trying ...
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0answers
10 views

How to compare the change (increase or decrease) for two pairs using one-way Wilcoxon signed-rank test?

Suppose I have $X_{before}$, $X_{after}$ and $Y_{before}$, $Y_{after}$ (before and after the drug). Each variable have 15 observation, i.e 60 in total. I used one-way Wilcoxon signed-rank test to see ...
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0answers
33 views

Compare two sets of correlations

I have two sets of pairs: <distance, correlation> where the correlation is the Pearson coefficient between two samples, ...
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1answer
15 views

How to compare two sets of time-series 3-Dimensional data?

Let us say we have two data sets. Each of the data sets has velocity $(v_x,v_y,v_z)$ and acceleration $(a_x,a_y,a_z)$ of particles at time steps n where $0 \leq n \leq 100,000$. Now how do I compare ...
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0answers
18 views

Calculate r from paired-samples t-test or from repeated-measures ANOVA?

Is it possible to calculate a correlation coefficient (r) from F- or t-statistics in the case of paired samples? The bottom comment on this page seems to suggest that you would calculate it in the ...
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1answer
33 views

Paired sample t test

I have developed an Interactive Genetic Algorithm for my thesis and I need to find out if the mean population fitness at generation 5 is significantly different from the mean fitness at generation 10. ...
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0answers
16 views

Comparing corpuses with different vocabulary?

How can we compare two corpuses with different vocabulary? Basically, we have a bunch of distributions for different vocabularies that we want to compare. But all the vocabularies are different ...
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0answers
30 views

Crossover study, multiple measure

I'm trying to analyze data from a crossover study, where two treatments ($A$ and $B$) are applied to $n$ patients (each patient receive both treatments). For each treatment I have an outcome with ...
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0answers
95 views

Paired t-test vs Wilcoxon signed rank

I conducted a pilot study (n=14) which was evaluated retrospectively. I have four parameters with a pre-intervention and post-intervention score that I want to compare. I am wondering whether I can do ...
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1answer
36 views

Can a paired t-test be used with the number of words recalled?

I recently went to a 3rd grade level science/math school exhibition, where someone had posted this data on how well people remember words, when they read it in a book vs a tablet. There were in total ...
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1answer
46 views

Effect size (cohen's d) when mean and SD are zero

I am calculating effect sizes (Cohen's d) for a meta-analysis to examine pre-test to post-test differences after receiving a word-learning treatment. I am using pre-test and post-test means and SDs in ...
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45 views

How to compare means of two sets when one set is a subset of another and the sample sizes are not

I have two samples containing citation counts for some publications. Of those samples one is a subset of the another. That is, subset contains some exact citation counts appearing on the other sample. ...
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1answer
31 views

Degree of Freedom twice as much as it should be?

I am performing paired t-test as following: t.test(h1$pureinf_hvar, h1$pureinf_lvar, alternative="greater", Paired=T) having each column of h1 (pureinf_hvar and ...
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1answer
82 views

Error in the design of an experiment

Suppose that we have a population with a subpopulation that exhibits a certain characteristic. We are interested in the performance of a group of people from the population on a group test. The ...
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0answers
30 views

Price comparison statistics and data visualisation

I'm getting into learning statistics and was hoping you could give me some pointers on where to go with this experiment. Basically I'm trying to compare prices for same/similar items across a variety ...
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26 views

Difference in Means vs. Mean Difference: Confidence Intervals

This is a follow-up question to Difference in Means vs. Mean Difference. I am, however, interested in the confidence intervals for the difference of the means, and the mean of the paired differences. ...
10
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1answer
169 views

How to choose between sign test and Wilcoxon signed-rank test?

I am trying to pick one from these two tests to analyze paired data. Does anyone know any rules of thumb about which one to pick in general?
0
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1answer
37 views

Dependent t-test for matched pairs vs repeated measures

I am planning an evaluation which will deploy pre- and post-tests for one group of students. I would like to perform a dependent t-test but may not be able to perform a repeated measures analysis ...
23
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1answer
821 views

Have the reports of the death of the t-test been greatly exaggerated?

Reading through CV all-time classics I came across a statement that I would like to clarify. This is the post and my question refers to the closing remarks: "I have to note that all of the knowledge I ...
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20 views

Regression analysis for change in overall score of a likert based survey

We have a pre-post study and we want to assess the effect of an intervention on the change in the scores of a survey in a group of subject. The survey is made up of many likert questions. We will ...
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59 views

Nonparametric MANOVA for paired samples

I have a Test group(~ 20 subjects) and Control group (~ 20 subjects) on whom 10 sets of measurements (10 Dependent variables - DV's) exist before treatment. Post treatment (on the Test group) the 10 ...
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13 views

Linear regression with different samples of data: addressing compatibility and parameter estimation

I have two samples of data (call 'em black and red), spread like in figure. I ran a linear regression over both samples. I understand that they cannot come from the same joint pdf f(x,y), and that a ...
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0answers
63 views

Analysis of paired count data

I need to test data on patients in a pre/post setting. I have data on the counts of seizures in a starting interval, and then another count of seizures after the patient was treated for the same time ...
1
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1answer
48 views

paired t-test, 2 samples of different sizes

I have a population of interest on which one numeric variable has been measured twice: before and after surgery. I did a paired t-test to compare means of the variable. However, there is a difference ...
2
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2answers
63 views

Comparing variances of non-normal distributions

I have edited my OP to try and better explain my data and my questions. Background Info I have 34 species, and for each of them I identified "category 1" genes. Their counts are in the vector ...
2
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2answers
50 views

Interpreting wording for formulating hypothesis testing

I've been presented with paired data for individuals' weights before and after a dieting program (paired t-test problem). The question being asked is "test the hypothesis that the dieting program is ...
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0answers
28 views

Paired t-test with pairing based on dates?

I have the conversion rate of 2 pages per day during 30 days. I know that the conversion rate follows a daily trend and that could explain a lot of the variation. I want to check if the difference ...
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0answers
44 views

How to compare two different rankings of same set of objects?

I have $N$ objects $A_1,\dots,A_N$. I have two algorithms that assign two different scores to each of this objects. Thus sorting on this scores gives me two different rankings of these same objects. ...
2
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1answer
20 views

Test to evaluate if two delta values are associated?

I have an observational cohort. Subjects have lost weight. I wish to see if the weight they lost is correlated to an increase in break down of amino acids muscle. I have values from 2 time points ...
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0answers
35 views

Test for overlap between two sets of hypothesis tests

I'm looking for the appropriate test for determining whether the overlap in variables in which the null hypothesis was rejected is greater than expected by chance for two identical sets of independent ...
0
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0answers
20 views

What statistical test should I use? Paired t-test, $\chi^2$ goodness-of-fit or neither?

I am looking to evaluate rate of improvement of PAP results. I have total number of paps completed and of those a number were unsatisfactory for evaluation. I then had an educational session with ...
2
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0answers
37 views

Can I run a paired T-Test with two different sample sizes?

I recently ran choice tests for birds, to see if they preferred either food that they have waited for or food that they have not waited for. Each of the 8 birds had 15 tests, so I have 120 choices in ...
0
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0answers
47 views

Testing for differences between two treatments with repeated measurements

I am a little uncertain which test / approach to take for the following problem. I am using R. Data I have data from an experiment. The experiment has two different treatments and I ran a total of 5 ...
3
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2answers
110 views

Difference between confidence intervals and comparison arrows

I am using the R package lsmeans. On page 10 of the vignette (pdf), a way to show the comparisons between groups is described using: ...
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0answers
13 views

Pairwise comparison with repitition

I did a test where I have 7 audio systems which where compared with each other and the tester have to say if the second one is better or worse than the first (scale -3 to 3). After comparing all 21 ...
0
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1answer
118 views

Wilcoxon signed-rank test for proportion variable response?

My response variable is a proportion. The explanatory variable is categorical with two levels which are not independent. The distribution of the response variable is different from normal. ...