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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How to cluster data with repeated measurements?

Most clustering algorithms assume that data points in each row are independent. I have some data with repeated measurements from individuals. I can use a standard algorithm, and then check to see if ...
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Variance of difference of $x_{i,t}$ and $x_{i,t+1}$

We have $n$ observations of human performance before and after a training program. We have a random sample of $n$ individuals and assume population distributions are normal. We thus have: $x_{1,t},\ ...
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11 views

G and R matrices in mixed model and model selection

I have data in which the plants were subjected to four conditions and measured weekly for a month. I would like to incorporate "plot" as a random factor into my linear mixed model using SPSS. I am ...
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24 views

Analysis of a longitudinal study where interventions are received at different time points

I have a data set of university students. The university has 8 different assisting programs, mostly like scholarships, for needy students to help them concentrate on their studies. Since it costs a ...
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57 views

One observation per level in mixed-effect model

Field explains how to analyse repeated-measures data using linear mixed-effect models (LME). See Field et al., Discovering Statistics Using R, 2012, p. 573. However, the way he specifies the model, ...
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42 views

Measuring longitudinal data where individuals have missing observations

We have a longitudinal panel of X users with their online spending patterns and are trying to measure certain metrics within the panel. We have time series information about the users such as their ...
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41 views

How to test for differences among 3 treatments pre & post, all within subjects?

I want to compare the changes in blood pressure occurring following 2 anesthetic drugs. So in a crossover design, each participant comes for 3 sessions and gets either of placebo, drug A or drug B on ...
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27 views

How to determine which covariates to use

This may seem like a basic question but here goes... I am looking at the effect of brain stimulation on skill acquisition across several timepoints. I have several measures that may be useful as ...
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36 views

Few principles of linear regression

I have had hard time to find definite answer to following theoretical issue: Lets say I have data which has 20 subjects and same blood level measurement (repeated measurements) has been assessed in ...
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86 views

Summarizing and plotting several combined relationships with LMER

I want to see if there is a significant relationship between predictor and value. I've measured these two variables in 6 different conditions (not a full 3 x 3 design because feature1 and feature2 ...
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18 views

Interpreting an interaction in the presence of main effects

I'm having a crisis of confidence in my stats and I was wondering if somebody could help me. I ran a 2 x 2 x 2 x 3 repeated measures ANOVA and got: 2 main effects 3 2 x 2 interactions and a 3 way ...
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14 views

Longitudinal design: how to take into account baseline measures

I have a (small) data set of 15 subjects randomly assigned to one of two groups. All subjects were measured at 7 time points. Ideally, I would like to answer if the groups differ at certain time ...
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26 views

Why does my repeated measures ANOVA analysis vary when I organize my data differently?

In my study there were 63 types of stimuli (63 levels of the IV) and all types had 8 different examples (8 trials per level of IV) which were all categorized by each participant. Accuracy of ...
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28 views

4-way Repeated Measures ANOVA

exchangers! I am struggling with my data analysis for an article I'm writing. I have to following experimental set-up. Instruction (A/B) Group (Alcohol Dependent / healthy Control) - between ...
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33 views

1-Way ANOVA with single independent/repeated (within/between) factor

I want to perform an ANOVA on data with a single factor with three levels. The difficulty for me is that two of the levels are repeated measures (within subjects) and the third level is independent ...
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58 views

What is the lme4::lmer equivalent of a three-way repeated measures ANOVA?

My question is based on this response which showed which lme4::lmer model corresponds to a two-way repeated measures ANOVA: ...
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9 views

Two repeated measures treatment analysis. Regression of the delta or mixed effect model?

We want to study the effect of a certain treatment on performance on a test and I would like to have some suggestion from you. We want to use a regression model in order to control for confounders. ...
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28 views

Discrete Variables and Regression

I have only discrete independent variables (gender, religious affiliation etc) and continuous dependent variables. Is it possible to use a regression model?
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12 views

Moderated regression in repeated measures

I recently conducted a study with 4 within-subject conditions, divided over two sessions. My independent variable is degree of emotional eating (as measured by food intake after a negative mood ...
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36 views

How to report confidence intervals for an interaction?

I have a significant interaction in a repeated measures ANOVA. Two groups in my data are significantly different from one another. In order to report the overall confidence intervals, when I report ...
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Joint model for ordinal repeated measures data and MNAR dropout using R

I have a dataset consisting of repeated measures data of graded toxicity scores (0-4) in a large number of patients being treated with a anti-cancer drug. We would like to identify predictors for ...
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113 views

I just don't get the t-test

I know it sounds abysmally ignorant, but here we go. I understand the basic logic behind the t-test: you want to know whether the difference in the mean of two samples is due to chance or not. To ...
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34 views

Linear Regression with repeated measurements of replicate samples?

This is a simple question but I has bugged me for some time. Can someone please share a link, or describe, how I can perform a linear regression from repeated measures of replicate samples over a ...
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26 views

Two-way Repeated Measures ANOVA with replicated measures

My experiment involves 16 participants with a dependent variable (PP) tested under 2 conditions, across 3 different time-points. At every time-point, each participant is tested twice. My data is ...
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13 views

Pretest posttest regression

I am trying to set up a multiple regression for a pretest posttest dependent variable. There will be no control group, and we will be controlling for age (continuous) and gender. Want to use the ...
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Summary statistics & CIs for sample variances from multiple populations

Suppose $X_i$ are $n$ random variables that are all distributed normally, but with differing means and standard deviations: $X_i \sim N(\mu_i, \sigma_i)$. Now suppose $y_{ij}$ is the $j$-th random ...
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Normality test for repeated measures data

I've measured the motor function of the same subjects (n=6) over 7 different time points. I would like to know whether the mean motor function varies significantly with time (day 1 versus day 2 etc) ...
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66 views

repeated measures ANOVA, crossover trial, R

I am sorry for stating such a question. Unfortunatelly, it's very-very hard to go through all statistics. I have a crossover study design with 3 treatments, 3 periods, and a baseline (covariate). The ...
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Apparently varying effects in experimental replicates

We are testing whether Drug A increases particle count over control. When we were designing the experiments and knowing that there is a good deal of biological variability, we included both technical ...
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Comparing means between 3 categories across 10 subjects with repeated-measures

I have 10 animals ("fish") with 30 trials for each one of them. Those 300 trials are classified into 3 categories ("classification") and each trial is associated with a continuous variable ...
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51 views

ANOVA for paired data

I'm asking just of curiosity. If I have, for example, paired data and 3 groups (for example, baseline, 1 week, 2 weeks of treatment: I mean we take some samples at the baseline, then we apply some ...
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15 views

conditional independence in repeated measures design

How the responses are independent when conditioned on random effect in repeated measure analysis (linear mixed model)?
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35 views

Repeated measures ANOVA with replicated measurements.

I have performed an experiment testing 3 different modes of operation on 16 participants. Each mode of operation was tested twice per user. ...
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50 views

Effect sizes in within-subject design on R

I'm doing a meta-analysis but I need your precious help on couple things : 1) First, on R, in the compute.es package, I found only effect sizes computation formula ...
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96 views

Mixed, repeated measure model specification and results interpretation using LMER in R

I am working with data from a computer task which has 288 total trials, each of which can be categorically classified according to Trial Type, Number of Stimuli, and Probe Location. Because I want to ...
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12 views

Comparison test of reapeated Cohen's kappa

Suppose two raters judged a set of stimuli. Then Cohen's kappa was calculated as measure of inter-rater agreement ($\kappa_{pre-training}$). Suppose now that after a training session, the same two ...
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Factor analysis with repeated measures

Multilevel factor analysis seems to be the technical term for factor analysis with repeated measures, judging from this abstract. To be precise, following Wikipedia's factor analysis notation, the ...
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25 views

Power analysis for repeated measures design with ordinal response

I am designing a randomised pretest-posttest trial for which I'm trying to do a sample size calculation. My brain is about to explode from confusion, so I hope someone can help me. Just a little ...
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22 views

Testing significance of a treatment inducing correlations over a time series

Example data In the example dataset, there are 3 distinct biological measurements, over 3 time points (0,12,24hrs) for 19 individuals. These individuals have been divided into 2 groups: treatment and ...
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Pre-post analysis with multiple post measures

I am having trouble deciding what type of analysis to use for the following data: I have two groups (one control, one treatment) and took a pre-measure of my dependent variable, and then 3 ...
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38 views

Identifying outliers for within-patient numerical data

I have a simple dataset of people's heights, many people with measurements on multiple days (once a year for 10 years, say). I have the date of each measurement. Some of the height values are ...
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17 views

Variation of binary responses between repeated measures

I am bit confused in terms of analyzing my data. I have done an experiment which involves testing of detection systems with controlled footage.The footage has been grouped based on scene properties ...
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33 views

SPSS Contrasts for a Five-Way Within-Subjects ANOVA (Yes, You read correctly)

I have a 4 x 4 x 2 x 2 x 2 repeated measures design and I'm trying to test a contrast for just the first variable (here called "SOA"), averaging over the others, in SPSS. Initially, I thought it ...
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Probability of event happening when data is aggregated with many independent events over the course of time

Let's say you have $X$ coins, each with a differing probability of landing heads (e.g. coin 1 has 10% chance of landing heads, coin 2 has 20% chance of landing heads, etc.). Now, let's say that you ...
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16 views

GLMM - time or day/date as a random factor

I have searched for many days trying to find the answer to this question, and am still not 100% sure I am happy with my conclusion. I am interested in looking at the effects of environmental variables ...
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12 views

Standardizing unbalanced repeated measures data

I have a dataset of height and weight measurements for adult patients in hospital clinic and want to calculate a standardized measure of boy mass index (BMI). For a given pair of measurements, it is ...
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40 views

How to analyze full-factorial within-subject experiment with ordinal (likert) data?

How can I analyze an within-subject full-factorial experiment with ordinal data from likert scale (with repetitions)? I would greatly appreciate your help. Study design Here is a description of the ...
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119 views

Mixed model in SPSS with random effect and repeated measures

I am working on analyzing a dataset that involves repeated measures data. The data was previously analyzed by a colleague using custom code written in C++, but I have expanded the dataset and am ...
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24 views

Single Categorical DV (3 levels), and Single Continuous Repeated Measure IV: which test?

I'm a Ph.D. psych student and am having trouble finding information on which test to use for a continuous repeated measures IV and categorical DV. I would really appreciate some help with this. The ...
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24 views

Is it possible to measure the independent variable with part of the dependent variable

I have Beta as my independent variable and Economic value added (EVA) as my dependent variable. To calculate EVA I need to use Cost of capital and to calculate that I have to use Beta, so is it ...