The group-differences tag has no wiki summary.
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0answers
33 views
Performing comparisons after a cluster analysis
I have a data set of about 40 subjects, and 10 variables, some measuring performance on a task, and some measuring some characteristic. Each of the performance variables consists of the proportion of ...
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0answers
22 views
Calculate standard error of difference between groups with different N
I have two datasets $X$ and $Y$ that have paired data, however one of the sets is larger than the other. I am interested in the standard error of the difference $Z = X - Y$.
I guess I could use the ...
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1answer
28 views
How to compare differences between groups, when measured values have decreasing trend
I'm currently performing challenging analysis and I'm not sure how to continue.
I have three separate groups which had different procedures. In each of them there are four measurements (subjects were ...
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1answer
61 views
How to correctly interpret group differences with this PCA plot?
Background: I asked hundreds of participants in my survey how much they are interested in selected areas (by five point Likert scales with 1 indicating "not interested" and 5 indicating "interested").
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2answers
59 views
Comparison of differences between pairs of samples of unequal size
I have four samples $x_1, x_2$ and $y_1, y_2$ with $n_{x1} \neq n_{x2} \neq n_{y1} \neq n_{y2} $. I calculated, using a Wilcoxon rank sum test, that $x_1$ is significantly different to $x_2$ and ...
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2answers
94 views
How can I calculate the relative probability of each move resulting in a win, given historic win/loss data for the possible moves?
We are at a position in a game where there is a decision to be made. As there are relatively few game positions and possible moves, we have collected statistics from previous occasions the game was ...
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0answers
14 views
Quantifying magnitude with negative numbers [closed]
I have a multivariate parametric model for predicting how likely an outcome is to occur. I'd like to be able to describe the difference in the avg prediction for the smallest group and the avg ...
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0answers
73 views
How to test group difference between nominal and ratio data with nonparametric tests?
In my data the dependent variable ‘vocabulary uptake’ is measured as scores ranging from 0-10 and the independent variable is yielded from a ‘reading intervention’ with 4 different reading conditions ...
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3answers
56 views
Testing whether two groups formed from a continuous variable differ on a binary outcome
18 people, who have been divided into 2 groups based on the semiquantitative expression of a protein (low vs high).
Group 1 (low protein levels) has 6 people, Group 2 (high protein levels) has 12 ...
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13 views
Group statistics based on individual Granger-Causality Results
I am analyzing how external influences affect the activity of individuals in subgroups over time. To do so I calculate Grangers-causality test for every individual within the groups. My question now ...
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0answers
30 views
Gene expression statistical analysis
I need to confirm statistical difference for gene expression data, for two groups of data, standardized with different reference genes:
...
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1answer
44 views
What is the distinction between “relationships” and “differences” (particularly in the context of group differences on a numeric attribute)?
What is the distinction between a relationship and a difference in the context of statistics - if you have a nominal variable and an interval variable, when should you use a correlation to measure the ...
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34 views
Calculating differences between groups and across time (age)
Let's say I have data of one variable $V$ measured for two groups of individuals ($a$ and $b$) and I want to see whether there is a significant difference between them and over time, i.e. $V_a$ stays ...
1
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1answer
81 views
Best test to assess statistical difference between two groups on a set of 5-point questionnaire items
I have a set of data which contains answers to a questionnaire (questions about satisfaction rated 1 to 5) and some demographic information (sex, age). I can divide the data in two groups and I want ...
3
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2answers
71 views
Spearman Rho or ANOVA when examining effect of ordinal IV on continuous DV?
I have an ordinal independent variable (<1hr, 1hr, 1-3hrs, 3-5hrs, >5hrs) and an interval dependent variable (test scores). Apparently I am expected to examine the relationship between the two by ...
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25 views
Changing the effect measure flips the estimated direction in a Bayesian difference-in-difference analysis
Within a Bayesian model, I have binomial rate parameter estimates for 4 groups, A1, A2, B1, B2 (4 parameters in a larger hierarchical model) which are on a 0-1 scale, so there are posterior samples on ...
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0answers
59 views
How to evaluate differences of multiple likert scale ratings of multiple items within groups?
I have data where different reviewers rated how important multiple topics are on a scale of 1 to 5 (likert scale). Each of the topics is assigned to a group. I want to see if there any differences in ...
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4answers
104 views
Grouping samples by clustering or PCA
If I have 5 binary variables with values for 100 observations to give me a 5x100 matrix.
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0answers
75 views
ANOVA and significance test for multiple groups
I am currently investigating the mousemove behavior of users while working different kind of searchtasks in wikipedia. I've isolated a certain number of move-flows and gathered data for each of them. ...
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33 views
Comparing difference scores between 2 groups over 2 conditions
I am investigating a common discrepancy between male and female self-reports on a survey about sexual experiences. Generally, women report ~2/3 higher rates then men do. I have modified the survey ...
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0answers
71 views
Group differences from a Bayesian Hierarchical Multinomial Model in Jags
I'm unsure about how to go about looking at group differences in frequency data using a Hierarchical Bayesian approach. Normally I would do a Chi-square Test of Independence between groups, but this ...
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0answers
66 views
Nesting and grouping formula confusions using lme
I've seen a fair few of these posts already, and I feel a bit silly for posting yet another question on the topic - but I just cant seem to get my head around it. I'm very new to R and esp new to lme, ...
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0answers
58 views
Multiple t-tests against a single control condition. Is this correct?
I have a control condition A and several other conditions (B, C, D, etc.) against which I want to test A for differences (i.e. A vs B, A vs C, A vs D, etc.).
Is it correct to run:
ttest(A, B);
...
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0answers
90 views
How to determine post-treatment weight with uneven time points?
really appreciate your input on how to deal with uneven time points and missing data in a single-group repeated-measures design.
BACKGROUND: A group of 220 subjects went through a 4-month weight loss ...
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1answer
45 views
General rules for forming groups for analyses
I am analysing EEG data. I have data from 19 electrodes from 25 participants divided into two groups (11 and 14 subjects). I asked my student to compare this two groups with some statistical test. ...
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0answers
32 views
What test(s) for my data?
I'm trying to analyse data for my psych undergrad dissertation but struggling with which tests to use because my project is unlike anything I've had experience with previously (and also I don't have a ...
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0answers
38 views
Mean group score vs each individual participant's score?
I am conducting a questionnaire-based study with N=99. The participants are school-age language students who were tested in 9 small groups of size 10-12 drawn from existing school classes. The meat ...
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1answer
81 views
Multiple endpoints in survival analysis of individual careers
I analyze labour market activities. I measure JD: job duration (time between beginning and ending of employment) and PD: ...
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0answers
94 views
Analyzing test scores with different size groups
I'm a bit new to statistics; I know some general info about ANOVA, but I'm wondering if it's applicable in the following situation.
Let's say I have a group of people who have taken a test, and the ...
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0answers
154 views
How do I conduct an analysis of an interrupted time series design with a comparison group?
I am not sure if this is the right place to ask this question (if not, please refer me to the right place), but it would be nice if someone could help me:
Description of the Data/the Scenario:
I ...
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1answer
119 views
Differences between groups
I am currently doing a research on effects of writing styles on the perception of reader.
Currently I have the following 4 groups
...
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0answers
88 views
How to compare ranked data?
I have some questions about how to analyze ranked data.
The data looks like this: 4 groups of people with HIV and 16 other groups of people living in the same village were asked to rank 12 ...
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0answers
44 views
Is there a KS test for panel data?
Wikipedias says
In statistics, the Kolmogorov–Smirnov test (K–S test) is a
nonparametric test for the equality of continuous, one-dimensional
probability distributions that can be used to ...
2
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1answer
64 views
Matching covariates between more than 2 groups
I have three groups that I would like to match on age and gender. They don't need to be matched one-to-one, I just need group differences p < .05 for both variables. I can find packages that will ...
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0answers
76 views
How to test whether two means of categorisation generate significantly different results
If I have the following contingency table in which Novel.Cat is a new means of classifying some thing. Ref.Cat is the gold ...
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0answers
92 views
How to do a difference in means test for panel data?
I have panel data (5 variables) and binary outcomes (died, survived) for same individuals over few years (quarterly data).
If it wasn't panel data, it would be easy to perform "difference in means" ...
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2answers
258 views
What is the equation for combining standardized mean differences across multiple studies?
I am trying to come up with a combined/pooled standardized mean difference for meta-analysis of a dozen or so studies that have the same binary predictive groups and the same continuous outcome ...
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0answers
75 views
How to analyze differences of two groups with replicates?
I am trying to see if there are differences between two groups (background genetic mutants) and some values associated to them. Every group has 4 different gene types with two replicates each and its ...
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2answers
78 views
Difference between two groups of unequal age
This is probably a very simple question! I am trying to compare two groups on a balance evaluation, a normal group and one with a neuro deficit. However, these two groups are significantly different ...
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1answer
238 views
How to test for differences between two group means when the data is not normally distributed and the sample size is small?
I have a preliminary study with very small sample size (n=26), and I want to test for differences between males and females and similar things, so I have to divide the sample and make comparisons of ...
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1answer
159 views
Comparing the result of a study which has unequal group sizes
I have conducted two user studies and in my studies I didn't have control over the group sizes. In each study users were put in groups and they were asked to perform some group activities. Here is the ...
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2answers
96 views
Should false discovery be controlled at the data acquisition level, or should this be at the data interpretation level?
Should false discovery be controlled at the data acquisition level, or should this be at the data interpretation level?
I have an experiment in which microarrays were used to quantify the expression ...
0
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1answer
26 views
Analysis of participant's results to see who is the most different
What I'm trying to do is analyse results for an experiment I have conducted. An example set of results is
...
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2answers
216 views
How to test group differences when neither parametric nor nonparametric assumptions are met?
Consider following example. We asked 50 men and 50 women one question and they answered on 5 point likert scale (1 is completely disagree and 5 completely agree).
Suppose that 50 men responded 20 ...
0
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1answer
86 views
What is the most appropriate test for this situation?
I want to statistically test the mean difference of a continuous variable (let's call this variable 1) between four groups (nominal) in my sample. Variable 1 has a very skewed distribution.
This test ...
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2answers
125 views
Claiming validity of a study's negative finding
For a disease that I am interested in, five or six published works of research have shown an association of changes in gene expression with presence of the disease. However, all these diagnostic ...
2
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2answers
73 views
Difference in proportions but one of them is 0
What is the best way to test for difference of proportions when of them is 0% (or 100%) ?
edit: I have two raters, who give a score of either 1 or 0. One of them gave a 0 in every single case. Now I ...
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0answers
154 views
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1answer
129 views
Test effect of variable across sub-groups logistic regression
I have a logit model where I am predicting stunting (a binary indicator of malnutrition), and my two binary independent variables (improved.water and has.insurance) are both statistically significant: ...
2
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1answer
96 views
Estimating ratios of quantile means for sorted data
In studying the relationship between income and consumption, it is common to sort the observations by income and observe that high-income households have lower levels of consumption per dollar of ...
