Repeated measures data occurs when more than one measurement is collected on the same unit (e.g. subject). This data cannot be analysed through normal methods because the rows in the data are not independent due to the multiple measurements. The time sequencing of the measures may not be important.
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690 views
How to analyse repeated measure ANOVA with three or more conditions presented in randomised order?
Context:
My question concerns a typical design in my area – a researcher takes a group of subjects (say 10) and then applies three different conditions to them to measure the change in a response ...
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595 views
How to use G Power 3 to calculate statistical power in mixed design ANOVA with unequal group sample sizes
In G power 3, ANOVA repeated measures within-between interaction: Only the total sample size is reported assuming equal sample size for the two groups.
My questions are:
How would it work if the ...
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273 views
simple repeated measures syntax - lme vs. lmer
I'm trying to look for significant effects on "similarity" (of "isinpair" and controlling for time effects) using repeated measures with an in group sample. The intervention "isinpair" occurs after a ...
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373 views
How to compute confidence interval in ANOVA with repeated measures?
I made a model using repeated measures univariate ANOVA in R.
...
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0answers
87 views
Balanced repeated measures design
Okay this is my problem:
I have 12 participants.
Each participant spent 3 nights in my lab doing a reaction time task at four timepoints during the night(12, 1, 2 and 3 oclock), with one week ...
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445 views
Effect size measure for doubly-repeated measures design?
Update:
I haven't gotten any answers, so I am simplifying my question. Say I measure test scores of $100$ people in one of two conditions. Each test has $10$ items. On each item, each person can ...
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175 views
Is repeated measures ANOVA appropriate for my experiment and is my sample size large enough?
I'm really confused. I never took statistics but am trying to read up as much as I can. I didn't think much about statistical analysis until after doing the experiment, unfortunately, but maybe ...
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101 views
Multilevel modeling of experimental data with repeated measures in the same condition of factorial experiment
I'm struggling with modeling some experimental data using the lme4 package in R, and would appreciate input.
My experimental design is as follows: subjects ...
3
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126 views
Mixed models and normally distributed random effects
I am attempting to analyze some data that includes 10 repeated measurements on 10 different samples. This would normally require using mixed models, and I have attempted to model these using ...
3
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0answers
109 views
Specification of error terms in aov() in R
For a two-way repeated measures design, we can specify the model using aov in the following fashion:
...
3
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0answers
69 views
Modeling measurement error (reliability?) using repeated measurements
I have a measurement protocol that seeks to characterise the visual sensitivity of a subject. I would like to assess how reliable the measurements from this procedure are.
I have measured a small ...
3
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0answers
119 views
Repeated measures interaction betwen SNP and treatment with R
This is my first question is this forum. I have the a problem that I want to solve with the lme function of the nlme package of ...
3
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0answers
368 views
How do I estimate a repeated measures ANCOVA in R and SPSS?
I'm currently running a perception experiment:
DV: error (this in degrees- how much an observer was away from the real answer)
IV: the time bin (5 levels) in which the unique stimulus appeared
...
3
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0answers
129 views
How to tell if a continuous variable is associated with (treatment) change in another variable over time (one group, time 1, time 2)?
Hypothetical: I have treated a sample for depression and have (continuous) depression scores at intake (Y1) and at the end of treatment (Y2). I am wondering if motivation (X) at the start of therapy ...
3
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0answers
126 views
How to test for differences in binary score data?
I have data from a human subject study that was setup as a 3x2 (system by task type) experiment, with 24 participants. Each participant completed 6 tasks in all, one using each of the 3 systems, and 2 ...
3
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0answers
160 views
How can I compute a repeated measurement ANOVA with a mixed model?
It is my task to program a mixed model. The data is from 20 experimental subjects, who were measured under 2 factors. Factor A has 7 levels, factor B has 3 levels. So, that for every subject I got 21 ...
3
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0answers
142 views
How do I derive principal components taking account of repeated measures?
I have data from a 24-item (each item ordinal) scale used at two time points in 2 groups - before and after treatment with treatment A and treatment B. I want to capture a core group of symptoms that ...
2
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0answers
26 views
Repeated measures ANOVA in R for non-orthogonal design
I have data from a two-factor within-subjects experiment design where the conditions are not orthogonal. Factor one (Location) has three levels; factor two (Stimulus) has three levels, one of which is ...
2
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40 views
Pretest-posttest plus control design
I am evaluating the effect of an intervention (treatment: a lecture) on the ability to spot behavioral clues of emotions using visual stimuli using pretest-posttest plus control group experimental ...
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0answers
40 views
Two uneven groups (101 vs 21) measured twice; what repeated measures ANOVA equivalent can help?
I have a question that I have difficulties in answering:
I have two groups of patients tested twice at the same continuous variable.
Group A=104 & GroupB=21.
So two groups, one continuous ...
2
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0answers
34 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 ...
2
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0answers
134 views
How to construct GLMM model for repeated measures with binary responses with lmer
In my experiment I assigned subjects to one of the 3 treatments A, B or C. Within each treatment, a single subject was tested with two models sequentially. The test sequence was randomized. The ...
2
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0answers
82 views
Nested repeated measures analysis
I have a nested repeated measures question. I have 20 individuals grouped into 5 families. For each individual I have measurements on subsequent days pre, during, and post-treatment for a total of 6 ...
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177 views
2
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61 views
mixed ancova or difference scores?
I am puzzled with how I should analyze the following data:
The dependent variable is respiratory sinus arrhythmia, a measure of parasympathetic activity (RSA). I have a $5\times5$ full factorial ...
2
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0answers
132 views
Use of nlme for mixed models of repeated measures with two classifying factors and a covariate
Suppose we have a mixed model for repeated measures with response being $y$ and a covariate being $x$(say, age). There are two classification factors $a$ and $b$. Say, 5 psychological patients($a$) in ...
2
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0answers
55 views
ANOVA variable that is both BETWEEN & WITHIN
Does anyone know how / if can you treat an independent variable as BOTH a between AND within subjects variable (ideally in SPSS ANOVA-repeated measures). That is, we have a repeated measures study ...
2
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0answers
65 views
Best practice when analysing placebo-controlled within-subject designs
I would like to analyse data from a placebo-controlled within-subject design. For every subject a numeric outcome variable (Y) was measured twice - once following administration of a drug and once ...
2
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0answers
97 views
Effects of multiple within-subjects factors when not all combinations of levels are available
My question: how can I analyze the effects of multiple within-subjects factors when my design does NOT include the all combinations of their factor levels, as would be required by a standard factorial ...
2
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0answers
139 views
Longitudinal design - repeated measures, non-parametric, non-balanced design
I am currently trying to find the best way to analyse my data.
Participants were tested longitudinally on up to five occasions. On each day participants were assessed for the presence or absence of a ...
2
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0answers
66 views
Data fitting with repeated measurements
we have an experiment to excite a system with some energy, then measure the decay as a function of time. We are measuring data at 4 times $t$ to fit to an exponential model: $y = a \exp(-t/p) + c$, ...
2
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0answers
61 views
How can I test for significance of a treatment in an unbalanced, repeated-measures experiment using R?
CrossValidated Community,
I must mention that I am a first-time poster (and relatively new to both modelling and R), so please excuse any norms I may violate in my post and politely inform me.
I ...
2
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0answers
65 views
What are good values to assume for correlation and sphericity when estimating sample size for a within-subjects design
I am planning a within-subjects study with four different conditions and I am using G*Power to calculate my needed sample size. Not being intimately acquainted with the intricacies of statistics in ...
2
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0answers
60 views
Effect of duration of treatment on the outcome at different time points
I am interested in knowing if the duration of treatment has an effect on treatment with two different drugs. We have used two different drugs to treat cerebral ischemia (brain damage) and continued ...
2
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0answers
120 views
Mixed model in R with paired design and covariates
I make habitat suitability models for animal species. The purpose of my research is to investigate the accuracy of different models.
I clearly have a nested design:
accuracy_measure -> response ...
2
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0answers
112 views
How to estimate the covariance matrix for repeated measures data given summary statistics?
I've been working on a power analysis for an RCT study for a psychological intervention. And I've been wondering how one would estimate the covariance matrix (or rho) for repeated measures data? This ...
2
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0answers
578 views
Non-normal and heterogeneous data with repeated measures ANOVA
I have run a repeated measures ANOVA using 3 groups and one factor with two levels.
I have discovered that the data are not normally distributed (but not badly), nor is the variance homogeneous in ...
2
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0answers
221 views
One-way repeated measures ANOVA and missing data
I have following data for the one-way repeated measures ANOVA test and I don't know how to deal with missing values.
The data looks something like this:
...
2
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0answers
259 views
Controlling for a variable in a GEE using SPSS
I have a dataset which I think would suit GEE. I am trying to assess the relative contribution of a number of simultaneous predictors and their interactions to the intensity of hurt feelings. I asked ...
2
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0answers
34 views
How to compare first to second half of measurements in a counterbalanced behavioral experiment?
I want to compare measurements in two halves of a behavioral experiment to examine for learning effects. My first course of action is to split the measurements in the two halves and then repeat the ...
2
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0answers
137 views
Can I used a repeated measures ANOVA or do I have to use a multivariate ANOVA?
I don't feel very comfortable with stats (still using simple programmes like SPSS rather than R!), and have a question about which is the best test to use with the following design:
I have performed ...
2
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0answers
140 views
How to test and examine interaction effect in 2 by 3 by 6 mixed ANOVA design?
Background:
I have two groups of children - one group with normal hearing and one with permanent hearing losses - call them NH and PHL.
Each child has had a hearing test, consisting of 6 different ...
2
votes
0answers
111 views
How to do post-hoc contrasts on within factor depending on certain between groups in SPSS?
Here are my experimental factors:
within-factor (two levels): time1, time2.
between factor (four levels): 4 groups.
I want to test specific post-hoc contrasts comparing:
group1: time1 vs. time2
...
2
votes
0answers
407 views
Mixed model with repeated measures and both of two treatments with lme or lmer in R
I know just enough about lme() and lmer() to get myself by with simple models, and to get myself into trouble with more complex ...
2
votes
0answers
392 views
How to analyze an unbalanced within-subject ANOVA design?
I have data from an experiment involving 4 groups of subjects, 2 possible interventions first and 3 possible intervention at a 2nd point, repeated data measurements from each subjects multiple time ...
2
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0answers
123 views
Controlled experiment with binary outcome variable
I have data from an experiment where students were tested on multiple words for the correct pronunciation of a specific linguistic phenomena.
The experiment was done with a control and experimental ...
2
votes
0answers
123 views
Is it allowed to incorporate static covariates in Mixed effects models with time series data?
I was recently told that it is not allowed to include static covariates in mixed effect models. I can believe that this could be true, however, when I have time series data, and season is a grouping ...
2
votes
0answers
432 views
How to calculate if the between-subject variability is significant given repeated measurements?
I have a question that's been bothering me research wise. The situation is as follows:
We are measuring a quantity in
subjects for which we assume that it
differs significantly between
...
2
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0answers
94 views
How to know whether the six spatial features values (in 3-time period) significantly differ from each other?
I am currently bothered on how to statistically analyze my simple data as shown below.
...
2
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0answers
347 views
What is a good statistical test for independent replicates?
I have a series of measurements in which something is sampled and placed into either category 1 or category 2. I have 3x2x3 factors for each set of measurements, and each set of measurements is done ...
