All Questions
1,501 questions with no upvoted or accepted answers
2
votes
2
answers
965
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Why do I get very bad fit indices for a moderation? (including a negative TLI!) / Multilevel Model
I'm testing L1 moderation models using Mplus.
I'm getting satisfactory fit indices for the model including my main predictor, then the model including a second ...
- 31
2
votes
0
answers
350
views
GLMM model formulation with a partial "subcondition"
I am modeling reaction times in a GLMM using the lme4 package. My data have the following structure:
Subject ID
Reaction times (RT)
Distractor type (Type): (3 levels): moving - static - no distractor
...
- 61
2
votes
0
answers
56
views
Can a grouping variable also be a predictor or vice versa
I sometimes see that a grouping variable such as study ($1,2,...15$) is used as a grouping variable to the right of the |:
...
- 4,056
2
votes
0
answers
32
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Multilevel modelling and cointegration, can the two methods be combined?
I am an epidemiologist, but not a statistician. I have a good enough handle on longitudinal multi-level models to push through the material and publish a paper, but my knowledge of all possible ...
- 21
2
votes
1
answer
181
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Meta analysis- multivariate or multi-level model?
I am conducting a meta-analysis to understand the impact of an intervention X on people’s responses as measured by three categories of measures. I have a couple of questions regarding the methodology:
...
- 21
2
votes
0
answers
172
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Different underlying parameter estimates for GAM fits
I'm puzzling over why I get dramatically different results fitting multilevel GAM models in two distinct, but closely related, ways. As a bit of background, I have a sample of 300 ...
- 21
2
votes
0
answers
2k
views
How to calculate CI for Median Odds Ratio?
According to Austin et al (2016) the median odds ratio (MOR) is defined by
$\exp(\sqrt{2\sigma^2} \times \Phi^{-1}(0.75))$
, where $\Phi^{-1}$ denotes the inverse of the standard normal cumulative ...
2
votes
0
answers
82
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Using the residual standard deviation of a weighted standard regression for effect size computation
I'm facing a trivial problem but I want to be sure that the approach is appropriate. I have a situation in which n subjects perform a task with k trials for each subject. k is not a fixed number and ...
2
votes
2
answers
2k
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Regression with multiple variables and time series (in SPSS)
I tried to find similar questions on this topic but couldn't find anything that helped me with my problem, so I will try to explain it on my own.
I'm trying to do a regression analysis on revenue for ...
2
votes
0
answers
446
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Multi-level repeated-measures logistic regression in python/R
Accidentally posted this in stackoverflow, so reposting here. I have a repeated-measures design experiment. Each subject took part in some experimental conditions, each one associated with several ...
- 207
2
votes
1
answer
221
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Can I see Log-likelihood values for two-step clustering in SPSS?
I need to compare Two-step clustering with latent class analysis. As LCA is not possible in SPSS I did it in R, however, 2-step clustering in R is quite challenging, so I did it in SPSS. To compare it ...
2
votes
1
answer
536
views
Creating a 2-level mixed model in SPSS to find predictors nested within subjects
I'm working with longitudinal data, and am using the mixed models function ins SPSS to look for predictors (level-1) nested within individuals (level-2).
If I add the participant ID as "subject&...
- 21
2
votes
0
answers
41
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What is a “batch” of coefficients in Bayesian multilevel modeling?
I’m well acquainted with frequentist approaches for multilevel models (i.e. mixed/random effects models with random intercepts or slopes), and empirical Bayes estimation, but I’m trying to get ...
- 6,020
2
votes
0
answers
276
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Comparing absolute rather than relative (percent) change in a negative binomial mixed effects longitudinal model
My question is:
Is there any multi-level method or library, preferably in R, that will predict a negative binomial outcome from multiple covariates and a “moderator," and then report on the ...
2
votes
0
answers
24
views
Is it possible/reasonable to use multimembership slope term?
I have been reading about multimembership models, in which there is a random intercept effect for each level, and an observation can belong to more than one of the levels - a simple example of a ...
- 41
2
votes
0
answers
397
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SEM for within subject data
My questionnaire is novle,100 listeners listen to 10 sound files and then rate each file on a 12-items likert type scale. So I have 100 participants but 1000 cases. Now my theory is 3 factors can be ...
- 63
2
votes
1
answer
325
views
Same odds ratio for both rows and columns
I'm getting stuck on how to run the odds ratio test for these two different questions:
Novice clinicians are more likely to use validated assessments than other assessments
Novice clinicians are ...
- 21
2
votes
0
answers
133
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Why do Bayesian hierarchical models converge where frequentist models do not?
I am analysing an experiment looking at abstinence rates among participants in a clinical drug and alcohol trial. There were two groups, those who received the new treatment and those who received ...
- 2,187
2
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0
answers
110
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Hierarchical models: what are the disadvantages of jointly optimizing first- and second-level parameters
Consider a hierarchical model. For each observatory unit $i$, we observe a vector of Data $D_i$, and we define some probability (density or mass) function $P(D_i|\theta_i)$, which is governed by a (...
2
votes
0
answers
72
views
Account for variance differences in linear mixed-effect model?
I'm not an expert statistician so excuse me if the question is trivial or not clearly written. I'm performing some statistical analysis of experimental psychology research.
Basically, I have an ...
2
votes
0
answers
440
views
heteroscedasticity in a linear mixed model of longitudinal data
I want to evaluate the effectiveness of a psychological intervention in a RCT. My study consists of 150 subjects. Half of them were assigned to the intervention group. They are nested within three ...
- 53
2
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0
answers
34
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Modelling how test agreement varies as a function of a covariate
I have a group of human subjects who have been given two versions of a test measuring the same outcome. I am interested in the agreement between these two tests, and whether their agreement varies as ...
- 3,833
2
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0
answers
45
views
Multilevel Analysis for count variable
I have a general question about multilevel analysis and have therefore created a minimal example to represent the data I want to analyse:
...
- 161
2
votes
0
answers
20
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Taking the square root of my DV solved problems with scewness in residuals. What does this mean?
As you could probably guess, I am -very- new to both statistics and R. SO the obvious answer would be that I have to get home and study more, but I would also appreciate some pointers here.
I have ...
- 21
2
votes
0
answers
346
views
Interpreting ICC in 3-level logistic regression
I've run a 3-level logistic regression in STATA- level one is maternal health clinics (N=200), level 2 is the primary health care centres(N=41) which run the clinics and level 3 is the district(N=8).
...
- 21
2
votes
0
answers
31
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Multilevel regression meta-analysis : no existing package? (Edited)
The question is in the title.
Meta-analysis with binomial distribution
I'm trying to do a meta-analysis on occurence of an event across different studies. For each study $i$ ($i=1,\dots,N$), I have ...
- 173
2
votes
0
answers
207
views
How does Mediation Analysis Account for Covariates
Can anyone explain how mediation analysis accounts for covariates?
For example, when I run a simple mediation analysis with X predicting Y mediated with M -- what happens when I specificy PROCESS ...
- 367
2
votes
0
answers
29
views
Can I use item as random factor if not all participants saw the same items?
I'm running an ordinal mixed model on data collected from when my participants ranked 16 photos of people of who they think are most similar to them. Depending on the age of the participant, they ...
- 33
2
votes
1
answer
265
views
Should I standardize questionnaire responses prior to reliability analysis?
I have a multiple questionnaires with responses on Likert scales. They differ in that some are rated on a 7p scale, and others on a 5p scale. I would like to look at the reliability of each scale as ...
- 470
2
votes
0
answers
298
views
Different interaction p-values in R versus SPSS
I originally ran my data in SPSS because figuring out the lmer package took some time for me to learn. I spent a few weeks writing up a script in R, but my output in R is different than what I'm ...
- 147
2
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0
answers
176
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A nonparametric residual bootstrap for random-effects models
This question regards ideas from "A novel bootstrap procedure for assessing
the relationship between class size and achievement".
The authors first describe a parametric bootstrap for random-effects ...
- 843
2
votes
0
answers
62
views
Using random intercepts in a multilevel model as dependent variables in a linear model
I have a mixed model with 3 levels: individual, city, and state, and so I get random intercepts for both cities and states. I understand that since cities are nested in their state, their intercepts ...
- 21
2
votes
0
answers
66
views
Different variables for different subgroups of linear model
Let's say I have a multiple linear model for a population of the form
$y = \beta_0 + \beta_1x_1 + \beta_2x_2 + e$
There is a third variable I want to introduce that I believe significantly explains ...
- 121
2
votes
0
answers
87
views
In a Hierarchical Bayesian Model, how can we sample and see how a prior distribution looks like if it contains hyperparameters with hyperpriors?
I have a Bayesian Hierarchical Model that looks like:
\begin{equation}
Y_i \sim N(\mu, \sigma^2) \\
\mu \sim N(\mu_0, \sigma_0^2) \\
\sigma^2 \sim Gamma(1,1) \\
\mu_0 \sim N(0,1) \\
\sigma_0^2 \sim ...
- 4,260
2
votes
0
answers
234
views
Probability score for Hierarchical classification models
We've a hierarchical classification system in place; where each level produces predictions with a probability. Here's how the hierarchy is setup
Top level: 1 model; ~25 classes
Level 1: 25 models(=25 ...
- 21
2
votes
0
answers
257
views
Practical questions about cluster bootstrap confidence intervals
I want to estimate the accuracy of a machine learning model. I have an independent test set with a vector of trusted labels and a corresponding vector of model-based predictions. If I assume the test ...
- 4,857
2
votes
0
answers
359
views
Random slope random intercept model for two grouping levels
I'm trying to see how boldness of individuals change with time (plasticity in personality). My data consists of boldness scores (response variable), Trials (across time), individuals nested within ...
- 57
2
votes
1
answer
154
views
Three-level meta-analysis with dependency on two levels
I am conducting a meta-analysis on the effect of conscientiousness on scholastic achievement in high-school students. Currently, I am struggling to find the right statistical analysis for my data ...
- 21
2
votes
0
answers
294
views
clustered multi-reader multi-case/modality ROC analysis in R
My problem
I am looking for an R approach to:
do a ROC-Analysis of (clustered (i.e. several observations per case, e.g. prostate segments) / multi reader / multi case/motality) rating (score 1-5) ...
- 215
2
votes
0
answers
141
views
Specifying a slopes-as-outcomes model in R
I have read some of the other threads and wanted to check my understanding of exactly what I am asking R to do. My code is:
The slopes-as-outcomes multilevel model i wish to test is:
Level 1: WPMSP =...
- 21
2
votes
1
answer
331
views
How to analyze the frequency of correct/ non-correct answers
I have a question about how to analyze some data. It involves the performance of two equally sized groups in a questionary with 30 arithmetic questions that I scored with two possible outcomes (...
- 51
2
votes
1
answer
71
views
Repeated measures, multilevel regression or another type of analysis?
I'm doing an experiment for which I've distributed a survey. People were asked in this survey to rate the attractiveness of 5 other people. I provided four groups of pictures and 1 of those groups ...
- 21
2
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0
answers
51
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What is the appropriate analysis for this type of repeated measures multi-binary data?
There is a popular theory within psychology that certain emotions will trigger "prototypical" facial expressions defined by the simultaneous contraction of specific facial muscles. For example, if a ...
- 4,857
2
votes
0
answers
123
views
Is a three-level multilevel model appropriate for my research question?
For a study that is currently in the planning stage we are considering what kind of model would be most appropriate. We are interested in the interactive effect of a drug (vs. placebo) and hormone ...
2
votes
0
answers
31
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Incorporating knowledge of aggregate outcomes to constrain predictions on finer scales
I've got county-level longitudinal data on the timing of an event between the years 1998 and 2012, and I want to use it to form a predictive model for the time that that event will occur in future ...
- 13.7k
2
votes
0
answers
187
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multi-level Wilcoxon analysis
The question was originated from the paper [1] Table 3 [2], for every species, there was a data frame with two column: disease categories and the conservation index. Conservation index is numeric. The ...
- 269
2
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0
answers
621
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Multinomial (Categorical) Multilevel (Hierarchical) Bayesian Model in R
I have a couple of questions, so I hope it is ok that I ask them here.
Before that, here is some background information on my data:
Outcome variable (1): categorical, 6 categories, N=168
Predictor ...
- 21
2
votes
1
answer
88
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Intraclass Correlations for Intraobserver-Reliability in Hierarchical Data
We have a dataset where multiple measurements of the same variable are taken from individuals and we want to measure the intraobserver reliability. However, the individuals each come from different ...
- 805
2
votes
1
answer
38
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Transforming IV food expenditures for logistic regression
For my thesis I made a prediction model for food security using logistic regression (n=210). One of the predictors included in my final model is 'food expenditures'. The independent variable is ...
- 21
2
votes
0
answers
76
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Calculating a similarity score based on both nominal and scale variables
I'm currently writing my master thesis on the importance of deep-level similarities between a mentor and mentee for the mentorship effectiveness.
In order to test this, I've had 5 respondents ...
- 21