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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Regression involving multiple measurements on known values (calibration)

Suppose I have two continuous variables Y and X and I want to predict a Y value given a specific X value. However, the dataset I have is composed of 15 particular Y values (that are known values) ...
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25 views

Cluster the repeated measure data

So I have the data that looks something like this ...
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13 views

Repeated Observations Due to Pairings in Logistic Regression

I have data with repeated observations within a given year. Here's a snippet of the data: ...
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12 views

How to test for interactions of continuous measure with two repeated-measures factors in R?

I am doing an items analysis of difficulty ratings of a large set of math problems which were constructed to represent the factorial combinations of two binary factors, feature1 and feature2. The ...
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48 views

Two-Way Repeated-Measure design with lme4

I would like to model a treatment effect in two different groups, controlled for some co-variates (like age and education), and I assume that a two-way repeated-measure Anova would be the right ...
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18 views

How to analyze ranks as responses?

A client has data where multiple subjects (people) have been presented with with four product alternatives, and after experiencing all four, were asked to rank the products. The data look like ...
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11 views

validity when between subjects factor makes group size uneven

I'm doing a repeated measures analysis and, while I have even amounts of samples for each subject, and the variances and sphericity are fine for the dependent measures, I'm worried because I have ...
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21 views

Comparing Binomial Success Parameters in a Stratified Approach - An Example in Biostatistics

I would like to contrast the effectiveness of drug treatment and surgical treatment in a study with the following data. Each row represents one trial, and each trial uses either drugs or surgeries to ...
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4answers
294 views

Develop a statistical test to distinguish two products

I have a data set from a customer survey, I want to deploy a statistical test to see whether there is significance difference between product 1 and product 2. Here is a data set of customers' ...
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8 views

Converting Repeated Measures Code in SAS to Equivalent in R [migrated]

I am attempting to convert existing SAS code I have for a research project into R. I am, unfortunately, finding myself totally clueless on how to approach this for repeated measures ANOVA despite a ...
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Comparing two means that are dependent

I have a data set concerning age-specific reproductive success in mountain goats. The explanatory variable is age and the dependent variable is the proportion of females giving birth. From ages 3-7 ...
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7 views

Use clustered S.E. or FE/RE for binary data in an experimental within-subject design?

I am analyzing a 2x2 experimental within-subjects-design, i.e. I have data from all subjects for all four possible treatment combinations. Lets say treatment X has states X1 and X2 and treatment Y ...
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11 views

What is going on here? Omnibus repeated measures ANOVA is marginal, but follow-up planned pairs <.05

I have a repeated measure ANOVA with a decent sample size (124 participants, with a score for each person for 3 conditions). The data are moderate to strongly positively skewed, (though similarly). ...
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27 views

McNemar's Test for repeated sex ratio data

I have proportion data (sex ratio of a dioecious plant) for a population that was measured three times. I would like to know if a McNemar's Test is the most appropriate analysis to answer the ...
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21 views

How to model time-series data with nested random and fixed effects?

I'm analysing PAM fluorescence data from an experimental set-up that I duplicated from an earlier experiment with a missing control. That's why I haven't given the statistics of the experiment much ...
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1answer
15 views

Using subject-specific random intercept to account for repeated measures over time

I have an epidemiologic study on subjects with yearly repeated measures on a count variable as an outcome and various yearly measured predictors. The study population changes every year somewhat, so ...
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19 views

What post hoc test can you use after performing a McNemar-Bowker test?

I have performed a McNemar-Bowker test on pig carcass skin lesion scores before (time 1) and after (time 2) routine slaughter processes. Skin lesion scores range from absent (0) to severe (3). Is ...
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2answers
324 views

The fallacy of splitting data collection time into shorter intervals to reduce error

Say you measure the (roughly constant) rate of something (i.e., counts of something per unit time) over 30 seconds, and you repeat this reading four times to find the mean and standard error of the ...
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14 views

ANOVA based on mixture of within-subject and between-subject experimental design

I have finished an experiment, and I used a mixture of within subject and between subject design, I am wondering if there is a specific name for this type of experimental design? I would like to find ...
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1answer
10 views

Statistical tests for a binary response variable with more than 2 repeated measures?

Question: Did plants experiencing treatment A vs. treatment B receive significantly more or less observations with zero visits from pollinators? Methods: Plants were clustered by similar physical ...
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12 views

About S/N and averaging

It is well known that Thus, in the ideal case S/N increases with the square root of the number of measurements that are averaged. (Wikipedia) The assumptions are that (1) signal and noise are ...
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13 views

Selecting best dependent variable in Repeated measures and multivariate data

I have a number of outcome variables both continuous, scores and categorical. I am trying to find the best methodology to select the best variable(s) among the many dependent variables that gives me ...
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1answer
19 views

Properly interpreting and presenting a differences in differences t-test in written and table forms

I have two separate groups of students. A control (n=23) and intervention (n=19) group. Both groups took a pre test measure (score of 0-100). I have done an independent t-test on the Post_minus_Pre ...
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1answer
23 views

Can I do a dependent t-test if pre & post were anonymous?

I am trying to analyze the following case study using SPSS. What I have done so far as part of my research is to conduct a case study to measure the affect the introduction of different technology ...
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Q1: Median Split and Q2: repeated measures multiple regression analysis

Question 1: I have performed a pretest in order to analyse which products are considered to be hedonic or utilitarian based upon characteristics. These characteristics were rated with a Likert scale. ...
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repeated measures mixed model with different number of measure per group

I have a an experiment with 3 groups. Two of these groups have the outcome of interest measured at baseline, 3 months and 12 months and one group has only been measured at baseline and 12 months. My ...
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Repeated Data Points, Weighted Linear Regression

Building on the question here; If every sample in OLS is repeated, then coefficients stay the same, but standard errors go down, and as a result, previously insignificant variables can become ...
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Analyzing Repeated Measures from Continuous Predictors

Calling all stats-fiends, and other quantitative thinkers - I have the following design: -A dependent variable (self-report measure) administered at 3 time points- -A set of continuous predictors; ...
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Analysis of survey data

This is the first time I am analyzing a survey. I have limited knowledge about stats and the best practices and would appreciate some pointers as to what kind of analysis I should perform on the data. ...
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1answer
20 views

How to Correlate Parameter Distributions Across Conditions Over A Subject Population?

I'd like some help trying to understand if the conceptual question I'm asking makes sense, and if so, how I would go about implementing the statistics for it. I designed an experiment with two ...
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1answer
40 views

One-way repeated measures ANOVA vs. two-way ANOVA

In a balanced repeated measures one-way ANOVA, we compare the true averages of a response variable across time points. Are the results about the time effects equivalent to those from a classic two-way ...
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contrasts between two grouped levels and the other six levels in a mixed 3x3 ANOVA in SPSS

I have a mixed ANOVA with 3 between subjects groups (control, m, s) , and 3 within subjects factors of stimulus type (3 levels), orientation (4), eccentricity (8 levels). i would like to investigate ...
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16 views

Which statistical significance test to use for nominal data collected from a within-subjects experiment?

I've collected some data from an experiment where I was evaluating a system. My independent variable had 4 conditions (call them C1, C2, C3 and C4). During the experiment, I asked six people to ...
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20 views

Including baseline values of dependent variable in growth model

I've seen different approaches to "controlling" for pretest values in growth models/linear mixed models. Here's an example from Tasca et al 2009: Here they include centered pretest scores as a ...
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29 views

Analysis for a repeated measures design with covariate that varies over conditions?

I'm trying to find the correct analysis that will allow me to carry out the equivalent of a repeated measures MANCOVA with a covariate that varies over three conditions. Basically I have an experiment ...
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non-uniform residuals in repeated measures mixed model; larger residuals further in time

I am analysing data from a longitudinal study in SAS and see time-dependent patterns in the residuals. Subjects in four groups (A to D) were given a treatment at time=0; and continuous response ...
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7 views

Correlation between ordinal and dichotomous variable with repeated measurements

I ask say 50 people to rate 10 statements whether they are true of false (dichotomous answer). The 10 statements were rated concerning the occurrence of specific cues (such as details or emotional ...
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23 views

Modelling time invariant variable as a random effect

I have a data set that consist of one-year claim information of individuals. Individuals can have zero claim, one claim and more than one claim in a year. Generally they have more than one claim and ...
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37 views

Discrimination between measurements made at different points in time

I would like to ascertain what variables discriminate best between experimental conditions in a repeated-measures experimental design. I have performed Repeated Measures MANOVA to determine whether ...
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11 views

Repeated measures ANCOVA - heterogeneity of slopes

In my 2x2x2 mixed model ANCOVA, the covariate is interacting with only one of the main effects (repeated measures). Would it be OK to interpret the rest of the effects and interactions (which were not ...
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24 views

One-way ANOVA: Concluding one true differences without any post-hoc tests?

Let's say that I run a one-way ANOVA with 3+ levels and that it comes out significant. Can I then, from this result alone, conclude that at least the two sample means that differs the most in my data ...
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1answer
36 views

How can I interpret a significant one-way repeated measures ANOVA with non-significant pairwise, bonferroni adjusted, comparisons?

I have a dataset with one factor consisting of four levels. I've run a one-way repeated measures ANOVA on the data, which came out significant. However, for the follow-up pairwise, bonferroni ...
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16 views

Association between two binary (yes/no) within-subjects variables

I want to examine the association between two binary variables (within-subjects data) but I'm not sure which test is most appropriate. Specifically, we asked participants if they had ever used a ...
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1answer
19 views

Repeated Measures ANOVA with randomly presented stimuli?

I currently have data that looks at participants receiving 10 stimuli successively, but the order the stimuli are presented changes with each participant. What type of analysis should be used to look ...
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5 views

How to analyse a longitudinal study with control and intervention groups, where the outcome is continuous but was right-truncated at baseline

A longitudinal anemia study right truncated hemoglobin levels at 12 mg/dl at baseline, limiting to only anemic participants (with hemo levels <=12). These participants were then divided to control ...
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45 views

Study on both hands of patients, mixed effects?

We want to test the correlation of a certain surgical procedure on the hand (carpal tunnel) and the development of trigger digit. We have both hands of the patients, some hands underwent surgery, ...
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1answer
12 views

Should I center time variant predictors in repeated measures multilevel models?

I have a multilevel model built coinsidering repeated measures on students. Students performance may vary depending on study hours and tutoring hours before each exam. Should I center the predictors ...
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1answer
18 views

paired samples (t-test?) with grouping variable

Im trying to determine the correct analysis for paired data with a grouping variable. I have 3 fish in each of 4 treatments, so 12 fish in total. Treatments are that the fish are fed at one of four ...
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22 views

Repeated measures for more than one variables

I wish to check if the covariate IVs $X_1$, $X_2$, $X_3$, have a significant effect in the way that the DVs $Y_1$, $Y_2$, $Y_3$ differentiates over time between two time points (2012, 2013). I have ...
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Repeated Measures Analysis for a Single Treatment with Missing Data

I have some data here that I am at a loss on how to analyze. The following data set represents a subset of some data I have where a number of subjects (4 here, about fifty in the actual set) ...