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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Relative risk estimation by Poisson regression with robust error variance

To estimate RRs for binary outcomes, sometimes the Poisson regression can be used. Specially in epidemiology, when the incidence rate of the binary outcome variable is above 10%, then it's necessary ...
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8 views

2x6 repeated measures ANOVA interaction and main effects question

Currently I'm graduating and I'm finishing up my master's thesis as we speak. It's a study about the effect of hand positioning on response time. I'm submitting my data to a 2x6 repeated measures ...
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11 views

T-test or repeated measure ANOVA?

I am a Phd student in neuroscience and not so knowledgeable in statistics. I have done an experiment and am not sure if i should use repeated measures ANOVA or independent T-test. The experiment is ...
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11 views

SPSS | Repeated-Measures ANCOVA | Covariate

We are performing a RCT with 4 groups (1 control + 3 experimental), where we measured physical activity (PA) at baseline, post-test and follow-up. Although we have done stratified randomization, the ...
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1answer
16 views

Time as random effect or fixed effect in glmmADMB

I have a longitudinal dataset where patients have a measurement with a date, currently coded as time from end of treatment (days). Now, I want to build a model. Roughly, a zero inflated Poisson model ...
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14 views

Generalized estimating equations - Multiple binary responses per condition (spss)

I have a repeated measures design. Each participant has two visits, one on placebo, one on drug. The task has a number of conditions. 'Target' has 2 levels, MS and RNG. Within the Target condition ...
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12 views

Permutation test for repeated measures (in time)

I have the measurements of a quantity, observed every day for 60 days Usually, this quantity is really near to 0, apart from 3 days where it is (significantly?) greater than 0 I thought it would be ...
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23 views

aov() and lme() give completely different results in analyzing repeated measures

I have data consisting of two measures per subject (variable score, measured at Day 0, and Day1 per each subject). There are two groups, and each subject belongs to one of them (variable Group). I ...
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7 views

ANOVA with repeated identical acquisitions (subject+treatment+tests)

I'm just reviewing an analysis done by an ex-colleague and am struggling to figure out whether it's been done correctly or not. I'm also not sure how to exactly call the model they employed. ...
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21 views

Meta-analysis: Calculating variance/ standard error of a mean difference for a within-subject design

I'm currently doing a random-effects meta-analysis. The studies that I'm analyzing come from a within-subject design where the same participants complete both the experimental and the control ...
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43 views

Model selection: testing the need for random-effects terms in longitudinal data

I have longitudinal data set where each participant was observed for 12 weeks. I followed this paper: Bliese, Paul D., and Robert E. Ployhart. "Growth modeling using random coefficient models: Model ...
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1answer
17 views

Repeated measures ANOVA contrasts

I'm running a repeated measures ANOVA with a 3-level DV. Now what I've read is that you only look at the post-hoc test if the within-subject (overall) effect is significant. What about the ...
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74 views

R vs SPSS - simple effects analysis in mixed 2x2 ANOVA scheme - same data, different results

I prepared a mixed 2x2 ANOVA design analysis both in SPSS and in R. The SPSS script is correct, but in R script there is a mistake somewhere. To test that I generated artificial data from a normal ...
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21 views

Setting Linear mixed model for within-subject crossed factors

I have problems in undertanding how to correctly run a mixed linear model. I have done an experiment to compare three groups (1 between-subject factor); for each subject, 2 sensory stimuli are given ...
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16 views

Unbalanced Repeated Measures Anova

First Question: I would like to double check that my code is doing what I think it is doing. I have two independent variables, Previous drilling and Soil Type, that are observational. Simpsons ...
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14 views

Which analysis is best for my data with repeated measures and 2 treatment groups?

I'm working in R. I have a data set of 21 fish, roughly half in each of 2 treatments. I measured their behaviour over 10 minutes and want to analyse this to look for changes over time (gradient) and ...
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1answer
30 views

Variance of Level 2 random effect depending on value of variable in highest level (Level 3) in Hierarchical model

I was reading material on hierarchical models, especially 3 level hierarchical models. One of the examples I found was having the hierarchy Hospitals-Wards-Nurses. Only 1 measurement per Nurse. So ...
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67 views

How to model a 2x2x2 dataset for a 3 way repeated measures ANOVA analysis

I have some data derived from a 2x2x2 experimental design. There are 3 IV's, each with 2 levels. My DV is reaction time (measured in seconds). I've used a repeated measures design (n=10). I have 20 ...
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17 views

What multivariate test to use when variables need to add up to a constant?

My data have three levels. The highest level is preferred vs. actual state. For each state there are 6 dimensions. Within each dimension there are 4 variables representing scores of 4 kinds of ...
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Increasing sensor resolution by repeat measurement

I have a thermometer which has resolution of 1C. The temperature is measured, the thermometer is reset, and the temperature is measured again. I'm looking for a formula to calculate how many ...
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21 views

Two way repeated measures with zeros, non integer values, and non-normal distribution

I would really appreciate some help with a few models I am trying to run. Essentially my data looks at how often a subject was visited depending on treatment and subject type across two years. The ...
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1answer
50 views

How to reconcile results from many incremental hypothesis tests?

I'm considering a series of controlled experiments (e.g. A/B tests) measuring the performance of a system. Each time a change to the system is found significant (via statistical inference) the test ...
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27 views

Why is the “sphericity assumption” in RM-ANOVA (constant variance of difference scores) called “sphericity”?

Why is the "sphericity assumption" in RM-ANOVA, i.e. the assumption of constant variance of difference scores, called "sphericity"? (This question was suggested in the comments to a related ...
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19 views

ANCOVA with ordinal covariate?

My study looks at the effects of sex on performance in a psychological task. There are 3 variables: sex (m/f), plus 2 within-subjects factors (with 2 and 3 levels), so it's a 2x2x3 repeated-measures ...
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130 views

How is repeated-measures ANOVA a special case of linear mixed models?

In this comment @gung mentions that On a different note, I think it's fair to think of RM ANOVA as a special case of linear mixed models. and a subsequent comment concurs with this. I ...
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19 views

Logistic regression repeated measures with binary outcome and continuous predictor

I am really a beginner in stats (and also in r) and would need a input on whether my statistical methodology for following research experiment is right: Study: I want to test the effect of the ...
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Test of Equality of mean for time series data

I want to test the equality of mean returns of 4 fund managers for seven time series data of annual returns, which statistical tools would be appropriate, i am planning to use single factor ANOVA
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8 views

Test for monotonic trends with repeated measures

I have a repeated measures design and I would like to test whether time has a specific, directional, effect on my dependent variable. I know that Repeated Measures ANOVAs are able to determine ...
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17 views

Binary outcome, prevalence at multiple time points

I have self-report data for diagnosis of a disease at four different time points for one population. What test should I use to compare the prevalence of disease at these four different time points in ...
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41 views

Using repeated measures change/trend as a predictor variable

I have repeated measures of happiness for a sample of participants, and a single measure of satisfaction for each of the ...
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1answer
52 views

Repeated measures on a small sample (n=3) with non-normally distributed continuous dependent variable

I would like to analyse repeatedly measured outcome (20 measures) data from an experimental trial I am running on three mice (n=3). My dependent variable is continuous but not normally distributed ...
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7 views

Intraclass correlation, multiple items per person

I am evaluating inter-rater reliability for acoustic measurements (formant frequencies) for vowel sounds. Data description: Subjects are recorded speaking 28 words, 7 words (5 different words, 2 ...
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45 views

ICC for inter-rater and parallel forms reliability with binary data?

I have 3 raters which each rate every file in a randomized set of files three times. Each file is rated as either a 1 or 0. I was hoping to assess the inter- and intra- rater reliability for the ...
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17 views

mean\medians as data points in two way repeated measures ANOVA

I have a table with 12 columns each regarding one combination of three (2X2X3) diffrent conditions in an experiment. Each row (25) represent a subject that did the experiment. Each data point in the ...
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13 views

Analyzing repeated cross-sectional surveys

I'm planning analyses for a substance abuse prevention media campaign and the funder is interested in looking at change over time in perceptions and attitudes towards drug use. We will take a sample ...
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11 views

Anova on repeated measures

I'm stuck with an Anova analyisis on repeated measures. I have the following dataset in long format After a meal, each subject in the study filled a nutritional questionaire on that meal. In ...
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21 views

Single subject independency of repeated measures

In part of an experimental trial (n=1), I asked the participant to answer a specific questionnaire (continuous response variable) under the influence of 4 different dosages (dosage 1, 2, 3 and 4) of a ...
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1answer
51 views

Three-level partially nested model

I am modeling change over time in group psychotherapy subjects using R and lme4. My data have the following structure: subject (id) time (code 1-10 for equally spaced repeated measures) outcome (for ...
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8 views

RM ANOVA in SPSS - 'Within' or 'Measure'?

I've gathered data on an experiment where my participants performed a task with 3 blocks. In each block, there were 20 trials, each offering them a choice between one of four options. So for example, ...
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22 views

How can I test the interaction of a 3-level, within-subjects variable with a continuous variable in R?

I would be extremely grateful for some advice on how to correctly fit linear mixed effects models with my repeated measures design! In my experiment, subjects completed a task with 3 difficulty ...
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19 views

Comparing groups with linear-mixed models

I have a problem with a dataset resulting from the repeated measurements of a clinical index on different patients. Each patient has been classified into two groups according to the index decline two ...
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8 views

Is it possible to get an interaction in Split Plot ANOVA (p = .02) and at the same time get a profile plot for estimated marg. M with no interaction?

In Split Plot/Mixed Design between-within (2by2 ANOVA with 3 DV) I got a significant interaction for one of my DV at F(1,196) = 5.467, p = .02. But when checked a profile plot for estimated marginal ...
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ANOVA single subject experiment

We have modelised an animal model to examine the distribution of a specific drug administered in two forms (either iv or per os) and a with a specific dosage (0.2, 0.4, 0.6, 0.8 ug for each ...
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1answer
18 views

What, if anything, is the relationship between random intercepts models and compound symmetry?

In the analysis of correlated data, you're often working with replicates where a worker does a task 2 or 20 times, or an individual is measured for blood pressure randomly over several times during ...
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8 views

Repeated measures ANOVA in a time series

I have a study design where 30 patients exercise breathing room air and then subsequently breathing reduced oxygen. Each subject has their cardiac output measured at 3 levels of exercise (low, medium ...
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15 views

How do I covary out a time-variable covariate in a repeated measures analysis?

I'm trying to analyze a longitudinal data set looking at pre- vs post-treatment effects on a single dependent variable. The difficulty I'm running into is that subjects in the group being analyzed are ...
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32 views

How to analyze dyadic repeated measures with categorical moderation?

I want to test the effects of the emotions expressed in private online chats between males and females (dyadic chats) on the female's satisfaction from the chat. And to test how some factors may ...
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19 views

How to correctly analyzed a mixed within-subjects/between-subjects design?

I recently ran a perceptual study in which I aimed to measure how emotion recognition accuracy from whole-body motions changed when two type of body representations were used. Five actors Ai with ...
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35 views

What are methods for computing the descriptive statistics of interval measures?

I do several measurements and obtain for each: $m_i = x_i \pm \delta x_i$. What are the mean and the standard deviation of a such series of measurements?
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Paired samples t-test (within-subjects) shows significant effect, BUT no main effect shows in Mised ANOVA - help!

Running some data looking at pseudoneglect: participants viewed figures that either had no change or small change in either left or right visual fields. t-test gave a signficant result, with ...