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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4
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1answer
61 views
+100

Computing Paired Samples (pre/post) Effect Size with Limited Information

I'm conducting a meta-analysis using the Hedge's g effect size statistic. Many of the studies are only reporting: pre-treatment mean score pre-treatment standard deviation post-treatment mean score ...
0
votes
0answers
3 views

Analysing matched pre post surveys that have definite answers

I have pre - post matched survey data that contains True/False responses and Multiple Choice responses. These questions have definitive answers, it is not a Likert scale. How can I compare the ...
2
votes
1answer
72 views

How can a paired test less powerful than unpaired test?

I'm using wilcox.test to compare two timepoints as such: a <- c(1,2,3,4,5) b <- c(2,3,4,5,6) wilcox.test(a, b) The ...
1
vote
0answers
15 views

How does a discordance test work?

Could someone explain how the discordance test works (and what it actually is)? The explanations I found online are unclear: [...] the concordance test can be viewed as the evaluation of the ...
0
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0answers
22 views

Consistent weight.matrix from the GenMatch (Matching package) in R

So I want to use the GenMatch function to generate optimal weight coefficients, to later use in the Match() function. But when I run the command twice, I do not get the same Matrix values. For ...
2
votes
3answers
79 views

How to measure the “confidence” that one set of values is greater than another?

I have a relatively simple task. I have collected several hundred samples from several groups (group here is arbitrary and not relevant to my question). These samples are scored on a continuous ...
0
votes
1answer
15 views

How should I present paired sample test results? [closed]

I conducted a paired sample t-test on pre and post questionnaire results. What should I be reporting?
2
votes
1answer
25 views

Regression Model for Binary Matched or Paired Contingency Table Results

This is a follow-up question on a prior thread about the same setup as follows: We have two "Methods" ("A" and "B") to diagnose a medical condition. We are not trying to determine which one is better ...
0
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0answers
15 views

pair-wise comparison for two sets of data where each point contains multiple values

I have two sets of data of the same subjects with 8 time points in each set.The second set is a repeated measure of the same 5 subjects. There are 5 subjects polled per time point. Is it correct to do ...
2
votes
1answer
28 views

Paired permuted t-tests?

I have a small dataset which are not normally distributed. I would like to perform a pairwise analysis of the differences in values between two groups. It has been suggested that I use permuted ...
3
votes
2answers
72 views

Mann-Whitney U test and paired data

I've read that working with paired data requires other method than Mann-Whitney $U$ test. I am not sure about how formally accurate is this statement. Reasons: Suppose that there is a set of $n$ ...
3
votes
0answers
29 views

Does conditional logistic regression effectively “throw away” concordant pairs like McNemar's test?

We are interested in analyzing pre-post data from a randomized control trial. The outcome is binary and I am trying to explain the heuristics of the model formulation for conditional logistic ...
0
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0answers
30 views

How to determine correct statistical test for repeated measures, differing treatments in same subject experiment

Our hypothesis is that treatment 1 changes our outcome measure by some amount, and that treatment 1 combined with treatment 2 changes our outcome measure by a larger amount. For each subject, the ...
1
vote
0answers
33 views

Which significance test can be used in this instance? - paired, non-normal means

I have a data set of behaviours for a herd of captive elephants which I have attempted to quantify to compare for statistical significance, i.e., if a behaviour is performed once during an observation ...
0
votes
0answers
17 views

Calculating unreported confidence intervals of ratios of paired means without raw data

I am brand new to this site and need some help in analysing some data in a systematic review I'm working on. I want to calculate the 95% confidence interval for the ratio of two means estimated from ...
2
votes
1answer
78 views

Permutation test: when the null hypothesis is **non**-equivalence of two models/predictors [closed]

Suppose I have two models $M_1$ and $M_2$ and I want to compare their performances in terms of measure (accuracy on classification instances, i.e. number of correct predictions to size of all ...
0
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0answers
17 views

Perceptual Agreement Statistics - Test for similarity between pairs?

I'm struggling to identify if there is a suitable and established test for determining if pairs formed from two separate populations are statistically similar when multiple people attempt to match ...
0
votes
0answers
30 views

Comparison of Non-Stationary Time Series Trends

I am trying to compare two readings of the same occurrences from two different sources, forming two time series. I would like to assign a metric to their similarity/dissimilarity, but the method I am ...
1
vote
1answer
27 views

Compare cumulative distribution functions of several function point counters

Function point counters are used to measure the size of software. However, they are believed not to deliver exact results. Different measurements sometimes produce different results. The performance ...
1
vote
1answer
27 views

Measure linear relationships between various variables

Different evaluation techniques were used to assess student’s programming ability in an introductory course (e.g. tests, practical exercises, final exam). Which statistical methods could be used to ...
0
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0answers
16 views

Chi square test and comparisons within this

I'm running chi square on a set of data that consists of frequency, question type, and participant group. I have an overall significant statistic but want to get p values for each question type across ...
1
vote
1answer
62 views

paired t-tests and interpretation of results

My study is about comparing the scores a group of students (sample, N=14) in two different conditions. They play the same game in a tablet and using a computer. They were administered with a ...
0
votes
1answer
40 views

Obtain adjusted means - Weight? Standardize? Use LSmeans?

I'm attempting to compare means from one year to another (and between groups at the same time point) by calculating adjusted values. I'm not sure what method to use. I've thought about the following: ...
0
votes
2answers
82 views

TukeyHSD multiple comparison on binomial data using Multcomp package in R

My question is how to perform TukeyHSD multiple comparison on ratio(for example, conversion rate, graduate school admit rate) using multcomp package in R. Take UCLA admission data for example: ...
1
vote
0answers
10 views

Compare non-gaussian distributions and evaluate sampling process

I have a 150,000 datapoints (continuous values between 0 and 1) and I am running a process that averages groups of smaller samples based on some other data values and results in ~100,000 datapoints. ...
4
votes
4answers
170 views

Paired t-test when each data point was repeatedly measured different number of times?

I have an existing data set that comes from the same group of people before and after they received a treatment. The data set comes from when participants tested their blood sugar values over a 30 ...
0
votes
0answers
25 views

When to plot different slopes for different treatments in ANCOVA

I am running an ANCOVA with a treatment of 3 levels and a continuous co-variate. Using step() in r, the simplest model includes the treatment factor and the co-variate, but not their interaction. To ...
1
vote
1answer
45 views

Is this a right way to use paired t-test

Problem Description I want to enhance a photo and I have 3 software to do that, out of which 2 are my own. I show users 2 photos and ask them to choose a better one. Now, I compare software 1 vs. 2, ...
0
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0answers
44 views

Logistic regression for paired comparisons

I am not a statistician; I'm an engineer, so much of this is a foreign language to me, though it seems like it wouldn't be that hard to understand if explained in a different way. I am trying to ...
0
votes
1answer
32 views

FWER correction for paired t-test

I have a continuous variable, and a small sample of 8 observations at 4 different time points (before some intervention, and at 3 follow-up time points). My sample, being a preliminary experiment, ...
2
votes
0answers
51 views

Am I using Paired Statistical Test Correctly?

I am comparing a feature between correct & incorrect trials. There are N=1194 paired samples $\{x_i,y_i| i=1,2,...N\}$, where x is for correct trials and y is incorrect trials. I am using a ...
0
votes
0answers
15 views

Comparing Learning Rates using Unit Curve in R

I have data for an experiment where 2 groups (Role) were tested over 3 consecutive trials for a task and time to complete task was recorded in sec. I wanted to compare the learning curves of the two ...
0
votes
1answer
21 views

Correction of mutliple paired samples t-test

In one group of subjects I have four parameters (for e.g. A, B, C, D) measured in two conditions. I want to know whether these 4 parameters differ between the conditions by doing paired samples ...
1
vote
1answer
86 views

Permutation on multiple Pairwise Comparison with least square means in R 3.1.2

I'm working on a study where I employed an analysis of covariance (Ancova) with unbalanced factors. I used permutation tests to obtain p-values for my estimates since my observation does not come from ...
0
votes
0answers
24 views

t-test for control and test group pre and post where pre and post subjects differ

I have been asked to help in analysing an educational intervention that has been completed, with a control and test group, pre and post tests to evaluate the effect of an intervention. It seems the ...
3
votes
0answers
47 views

Paired test using GLM with Gamma distribution

I know, that a paired T-test can be formulated in the framework of a linear model for gaussian distributions. I have two vectors of paired mesurements (rates under certain conditions) that follow a ...
2
votes
1answer
37 views

Paired difference test for nonhomogenous variances

Concrete scenario: A random sample of adults in Idaho rate each of 'kombucha', 'apple juice' and 'grape juice' on a scale from 0 to 1. Does the population of Idaho assign significantly different mean ...
1
vote
0answers
28 views

Significant difference within line set and between two sets of lines

For my research a person has walked on a treadmill which contains two pressure plates: One below the left foot, one below the right. I would like to compare the force in the z (downwards) direction ...
0
votes
1answer
29 views

Pretest-Posttest comparison

I am having a hard time doing this on Stata. I have a group of 32 students. All perform a pretest and are scored. Next, half of them are randomized to receiving an intervention and the other half ...
4
votes
1answer
58 views

When does an unpaired test result in higher p-value than a paired test?

I determined some parameter in a group of subjects under two conditions, such that each subject was tested in both conditions. I want to know if the condition has an effect on the parameter. My design ...
0
votes
0answers
20 views

When compare a variable in different times, one has normal distribution, another doesn't, which test should I use?

The question is to compare means of sales volume in different periods. So I got sales period 1 and sales period 2. Sample size is 40. The skewness, kurtosis, test of normality and histogram all show ...
1
vote
2answers
42 views

paired-sample t-test

I have taken weight measurements before and after a treatment. When I run a paired sample t-test and if there is a significant change, would it be possible to make the claim "95% of the time ...
2
votes
0answers
9 views

Appropriate correction for tests for determining best of family

I have a sample of $N$ instances of a problem (assumed to be independent samples of an infinite population of instances). To each of these instances I apply $M$ methods, and record how quickly they ...
2
votes
1answer
41 views

Longitudinal data analysis with a single group

I need you assistance with finding the right model to analyze longitudinal data with a single group. My data comes from the ophthalmic field, i.e. eyes. I have n subjects. For each subject, one eye ...
1
vote
1answer
22 views

math explanation for using paired-t

Not a math/stats person, but I am interested in finding out why "paired t" would be a preferred test for samples that are not "independent". I googled a bit on this topic, but didn't really find ...
0
votes
0answers
100 views

logistic regression with GLMM (and p-values)

It seems that I'm a little bit confused with the different ways to achieve its goals in the statistics’ world (and the R’s universe), so I’m asking your help about issues with which I'm struggling. ...
3
votes
1answer
112 views

Bootstrapping Hmisc::rcorrp.cens for paired concordance?

As Frank Harrell says here and other places, it's better to compare two predictive models (Cox proportional hazards in this case) wrt discrimination (C-index) using the paired U-statistic ...
1
vote
1answer
36 views

How to calculate correlations of matching pairs

I have very basic knowledge of statistics and would appreciate some help identifying an appropriate method to calculate the proportion of outcomes that agree between pairs of data and whether it is ...
0
votes
0answers
25 views

How to test differences in multiple pairwise distances? With mixed model?

I want to compare two set of variables: X1 = All the pairwise distances between individuals from group A and group ref R X2 = ALL the pairwise distances between individuals from group B and group ...
0
votes
0answers
15 views

lsmeans: how to have mean and SD from pairwise comparison? [duplicate]

In my previous question, I asked about effect size, but this question is about mean and SD from pairwise comparison generated by lsmeans. I am doing LMM starting from model comparisons. Then after ...