Tagged Questions
0
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0answers
18 views
Specifying a correct full model for an unbalanced repeated measures design in R lme4
Recently, I have done a fairly complex experiment, and I am having trouble coming up with a model that is suitable for the data. I have spent a few days reading about, e.g., when random effects should ...
0
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0answers
33 views
Book on Repeated Measure Analysis
Can anyone recommend a good book or some other reading materials
on repeated measure analysis using mixed model.Thanks.
Hanna
3
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0answers
120 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 ...
0
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0answers
48 views
Models with Nested Effects
I am having difficulty understanding nested effects. Suppose 20 people each are assigned to treatment groups A B C and D. Would it be correct to say that Person is nested within treatment group? So ...
0
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0answers
28 views
How can I analyse results from a repeated in repeated measures mixed design in r
I want to investigate performance in a learning test, where my test animals have been submitted to a number of trials within test day over several test days. I want to investigate if there is an ...
3
votes
1answer
169 views
Error term in repeated measures ANOVA in R
I am having problems with defining the error terms for a two way repeated measures ANOVA in R. My data consists of wood density estimates for three radial positions (inner, middle, and outer) along a ...
1
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0answers
137 views
Mixed model repeated measures, nested
I have a study in which I have 3 groups of crews (4 crews in each group) in
which there are two people (L/R). Each crew experienced 4 lighting treatments (D1-4),
once in one position, and again in ...
1
vote
1answer
230 views
Comparing groups at different time points within repeated measures study using SPSS
I have done a RCT (randomized control trial) of an intervention (which is of 6 week duration) versus control. The outcome measure (an exercise test) has been tested pre-intervention (Pre), immediately ...
2
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0answers
33 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 ...
0
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0answers
134 views
Interpretation of interaction and main effect in a mixed model when one is significant and the other is not
I have repeated (x4) measurements on 90 subjects. The outcome is zero inflated.
The model output gives these estimates:
...
0
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0answers
147 views
repeated measurements study using JMP - how to make a difference plot when data is unbalanced
My study is a repeated measurement design where I'm going to show reproducibility of pulse wave velocity measurements on minipigs.
I have read a lot of articles about reproducibility, both veterinary ...
1
vote
1answer
184 views
Negative and positive AICc/BIC for two models with transformed data - how to compare?
I am using AICc for model selection for transformed data (continous variable). One model I used $\log_{10}(PWV)$ as response and the other $\log(PWV)$ as response, but I am not sure which one to use ...
3
votes
1answer
171 views
Imputation for a zero-inflated negative binomial mixed effects model
I am working with a dataset of repeated (x4) observations on 100 subjects.
The outcome is zero-inflated and the data appears to be modelled well by a mixed effects zero-inflated negative binomial ...
2
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0answers
173 views
0
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0answers
277 views
Step-by-step mixed model analysis in R using lme, ezANOVA, or aov
My data consist of 4 treatments (fixed), 8 locations (2 locations per treatment), 3 positions (per location, fixed), 3 samples (per location, random), with dependent variable ...
2
votes
0answers
128 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 ...
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
votes
1answer
489 views
Using lme to analyse a complete randomized block design with repeated measures: Is my model correct?
I've got a completely randomized block design with three treatments and four replications. Biodiversity was measured in four successive years.
I figured that a mixed model with repeated measures as ...
5
votes
1answer
248 views
Repeated measures: aggregate, fixed effects, or random effects?
I have a repeated measures design with data collected across 8 treatments, with 5-6 repeats for each treatment in closely spaced time intervals (time is not important in the study). I only have 4 ...
1
vote
1answer
123 views
What is the ANOVA model to use for a 2x2 factorial experiment with units measured 3 times each?
If I were to set up an experiment examining the effects of exercise, and coffee consumption on the number of hours slept, what would the be the ANOVA model that I should use, given:
16 volunteers ...
1
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0answers
240 views
Mixed linear model with repeated measures in SPSS
I'm trying to run a mixed linear model analysis with SPSS. When I try to run the analysis, SPSS gives the following error message: ...
0
votes
1answer
1k views
Linear regression with repeated measures in R
I was unable to figure out how to perform linear regression in R in for a repeated measure design. In a previous question (still unanswered) it was suggested to me to not use ...
1
vote
0answers
277 views
Split plot design with repeated measures in package (nlme) - model errors
Forgive me if this answer is already somewhere on this site, but after extensive searching I have found nothing to help me. Here is a brief overview of the experiment:
I have 18 tanks, each of which ...
1
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0answers
103 views
Mixed repeated measures Anova
I'm trying to assess the influence of fertilisation and irrigation on biodiversity in a complete randomized block design. I have two treatments, one control and two blocks. Treatments went on for ...
1
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0answers
51 views
Analysing a balanced mixed models design?
I am designing an experiment and I'm in need of some help.
Participants are presented with two videos on a website. In one period, a feature (a table of contents for the video) is enabled, while in ...
6
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1answer
559 views
2
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1answer
787 views
How to interpret an interaction effect in SPSS output for a repeated measures anova with between and within group factors?
I have conducted a repeated measures ANOVA, with 2 factors:
One between factor (Ex_control: exercise intervention versus control)
One within factor (...
2
votes
0answers
119 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 ...
1
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2answers
2k views
Testing normality assumptions for linear mixed models and mixed (repeated) GLM ANOVA in SPSS
I have a mixed design that includes both repeated (condition) and between (sex and genotype) subjects factors. I would like to assess whether my data meets the normality assumptions for 1) General ...
5
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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 ...
1
vote
0answers
103 views
Repeated measures within and between conditions
I tested reactions to pictures under five conditions (neutral, high status, low status, high adhesion, low adhesion), using an EEG of 16 channels. The pictures were presented in random order for 15 ...
3
votes
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 ...
0
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0answers
84 views
What model should I use for comparing two techniques in SPSS?
I have 20 images taken from 20 subjects, two methods for analyzing these images, one as a reference, I want to see whether there is a statistically significant difference between the new method and ...
2
votes
0answers
129 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
votes
1answer
138 views
How do I predict subject mean (w/ error) with repeated measurements in SPSS?
Context: say I am trying to determine the concentration of a chemical, so I take known concentrations of the chemical and make a standard curve (6 measurements per standard) then measure my unknown 6 ...
9
votes
2answers
192 views
What model for a challenging data set? (hundreds of time series with a lot of nesting)
I have quite a complicated data set to analyze, and I cant find a good solution for it.
Here is the thing:
1. the raw data is essentially insect song recordings. Each song is made of several ...
1
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0answers
241 views
how do I fit a nonlinear mixed effects model for repeated measures data using nlmer?
I am trying to analyze repeated measures data and am struggling to make it work in R. My data is essentially the following, I have two treatment groups. Every subject in each group is tested everyday ...
10
votes
4answers
2k views
Example reports for mixed-model analysis using lmer in biology, psychology and medicine?
As the general consensus seems to be to use mixed-models via lmer() in R instead of classical ANOVA (for the often cited reasons, like unbalanced designs, crossed ...
5
votes
2answers
2k views
When is a repeated measures ANOVA preferred over a mixed-effects model?
In response to this question, regarding whether my design where I randomly presented participants with pictures from different categories was an example where I should use a repeated measures ANOVA, I ...
2
votes
1answer
639 views
How to analyze this dataset with 2 between-, two within- factors using lme4?
This post is a follow up on my previous post (which was interested in lme) and uses the same dataset. Now I would like to know how to analyze it using ...
4
votes
1answer
1k views
Is there a way to specify a lme model with more than one within-subjects factor?
The data
Suppose we have a dataset d with two between-subject factors (i.e., groups), group and ...
2
votes
1answer
1k views
Paired t-test as a special case of linear mixed-effect modeling (still unresolved)
We know that a paired t-test is just a special case of one-way repeated-measures (or within-subject) ANOVA as well as linear mixed-effect model, which can be demonstrated with lme() function the nlme ...
1
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0answers
265 views
How is the SAS REPLICATE statement in PROC NLMIXED different from a FREQ statement?
Note: I do not have access to SAS to work this out for myself.
I'm trying to work out the difference between the FREQ statement ...
1
vote
1answer
360 views
Repeated measures and random effects in R
I have an issue I cannot solve myself and hope I can get some pointers here:
I have a RCB design with 10 tree species each replicated 5 times in 5 blocks. I classified all species according to their ...
2
votes
0answers
402 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 ...
1
vote
0answers
39 views
Investigate change in mean levels of risk within a service- alternative to unbalanced repeated measures ANOVA
Not sure if this is as complicated as it's ended up in my head, here goes.
I have a series of measurements which measure how risk-prone psychiatric patients are (hereafter referred to as HCR and it's ...
4
votes
0answers
444 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 ...
1
vote
1answer
529 views
Why proc mixed give different DF than proc glimmix?
I am trying to move data analysis from proc mixed to glimmix for the easy of the ilink transformation. However I am finding a big difference on the denominator DF when using either of them. As ...
1
vote
1answer
140 views
What is the procedure for a mixed effects analysis of covariance?
I have 31 observations for 9 subjects undergoing therapy (4 session for 4 subjects, and 3 session for the rest). I have implemented a mixed model to assess relationships between the observations ...
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 ...
