Tagged Questions

Statistical methods appropriate for the analysis of data sets comprising several levels of hierarchy of units of analysis (e.g., students nested in classes nested in schools; observations nested in patients nested in hospitals). If you can refer to more specific models like mixed-model or glmm, ...

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11 views

Size multilevel logit model

I want to estimate a multilevel logit model. But I'm confused about the minimum number of groups and observations per group. What would be the minimum number of observations per group? My case: I ...
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0answers
14 views

Multilevel model for causal inference using observational data

I am trying to follow the lecture notes by Imbens/Wooldridge (http://www.nber.org/WNE/lect_10_diffindiffs.pdf) on difference-in-differences estimation. In page 4, they discuss the general framework ...
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16 views

Multilevel analysis, individual level and group level

I am investigating whether the air pollutant exposure during pregnancy has an impact on the infants' birth weight. The data I have include: 1)birth weight; 2)monthly air pollutant concentration ...
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7 views

multilevel of spatio-temporal model [on hold]

I need to code this model in software openbugs Many thanks for your help
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7 views

multilevel spatio-temporal

I multilevel model includes county, city and year that the number of cancer (cancer of the response variable of the model I use a Poisson response) at these levels have been calculated And I want to ...
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0answers
25 views

Explaining why the slope varies in varying slope model?

When I fit a multilevel varying slope model, it is easy to summarize the variation in slope. However, I have not yet seen any materials that discusses how to explain such variation (i.e. what about ...
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9 views

Multilevel model when treatment occurs at intersection of non-nested groups?

I'm formulating a multilevel model in which my binary treatment happens in certain country-years. In other words, the treatment is at the intersection of certain countries (group 1) and certain years ...
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6 views

validation analysis

I am using multilevel logistic regression (random intercept) in SAS (PROC GLIMMIX)in my research. My question is how should I do validation analysis? What do I need to report in my paper as validation ...
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1answer
20 views

Time-variant & Time invariant & Time-related

In Longitudinal study, What are "Time-variant covariates", "Time invariant covariates" and "Time-related covariates"? and what is differences between them?
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24 views

How to analyse binary outcome data with between- and within subjects factors?

I am looking for the right statistical procedure to analyse my data (mixed design) with binary outcomes. Between-subjects variable: treatment (yes or no); experimentally manipulated Within-subjects ...
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29 views

Principal components analysis on nested data

I'm working on a piece of analysis that requires identifying a small set of variables that summarize the variation found in a larger set of principal observations on teacher practice. Given the nature ...
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0answers
63 views

Multilevel analysis in R and Stata

I am trying to replicate a multilevel logistic analysis which uses a dyadic time series data set and R. As for my part, I am using the same data set but Stata. The original syntax has the following ...
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0answers
25 views

How to report mixed effects logistic regression

I have several models predicting different binary outcomes as a function of time (binary variable: before/after intervention) and age (ranges 4 to 14), measured in different students within different ...
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0answers
16 views

Comparing two curves with peaks

I have a question about analysis method and I would be very grateful for the help! So, I have two groups: Active and Placebo, each group is measured for 20 different concentrations (from 1 to 20) 6 ...
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0answers
9 views

initial status X time interaction

I am modeling change in a continuous variable over time using linear mixed modeling in SPSS. I would like to examine the possibility that initial status (i.e., pretest performance on the DV) interacts ...
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0answers
23 views

nonsignificant predictor becomes significant

This may be a question with an obvious answer. I am trying to predict change in a continuous variable over time using a linear mixed model in SPSS. There are 4 time points. Ultimately, I would like to ...
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0answers
11 views

multilevel mediation with a proportion dependent variable sem

I am attempting to test an indirect path in a multilevel dataset with an outcome that is a proportion. The data are a collection of variables related to various qualities of potential support ...
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0answers
29 views

Need help setting up multilevel logistic regression

I am trying to see the effect of a certain intervention in schools. The outcome variable is binary. We have students within schools. Also students' age is a covariate (doesn't changed before and after ...
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0answers
6 views

Quantifying Reliability of Qualitative Testing

If a visual grading system is implemented to calculate the correlation between exterior and interior conditions (i.g., good, medium, bad), and a sample is taken from a known population to test the ...
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0answers
23 views

Confidence intervals of proportions for clustered data

I am trying to compute the proportion of "yes"'s in data that is clustered (participants within cities). If I ignore the cities, I get very nice and narrow confidence intervals. If I compute the ...
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0answers
14 views

Estimating proportions in a non-nested multilevel Bayesian model

Data: x: 1/0 successes (~ 800 data points) c: city code (1 to 78) t: "time of measurement", 1 (morning), 2 (afternoon), 3 (evening), 4 (night) The problem: I would like to estimate the ...
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1answer
41 views

Undefined real result error at WinBUGS

I am currently working on my thesis and interested in estimating a multilevel differential item functioning model and I using at WinBUGS. Until I had done model check-up, there are no errors. However, ...
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0answers
27 views

Assumptions of Linear Mixed Model

I had data with repeated measurement and nested design. Conventional ANOVA requires strict control on homogeneity of variance and repeated measurement ANOVA requires assumption of sphericity. ...
1
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1answer
41 views

Multilevel: Can I include two dummy variables of a 7-dummy-set into a random slope?

I am calculating a two-level linear multilevel analysis. A look at the random intercept random slope model showed me a significant decrease in my model deviance if I include two dummy variables. Those ...
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0answers
15 views

How to share weights of between regression models when you learning them simultaneously?

I have many phenomenons which I want to model them as lasso regression problem. every phenomenon have it's own distinct features set. but for some phenomenons, the subset of features set are the ...
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3answers
70 views

Can I do a t-test to test significance? [closed]

I need a statistical test to determine if one group of ten classrooms with different numbers of students in each class has a class average on a test. Group two has 12 classrooms also with different ...
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1answer
79 views

Multilevel logistic regression with a random slope(s)

I would like to specify a two-level logistic regression model with random intercept and random slope. Dependent variable: hospitalization (1) or no-hospitalization (0). Independent variables: age, ...
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0answers
37 views

Fitting a partially clustered/nested design using lmer

I have a study where clustering occurs in one condition but not the other. In the treatment group I have repeated measurements on individuals who are nested within families. And in the control ...
1
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1answer
48 views

Cross-sectional Regression (individual level) with a few country-level variables

I have a small sample of 50 cross-sectional firms and 3 or 4 distinct explanatory variables -- all on the individual level. No time dimension. So far, I could employ OLS (I am using Stata: ...
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2answers
138 views

Is it ok to use a random intercept model without testing for random slopes?

In university we calculated a random intercept model for two-level nested data. We compared the random intercept model with all level-1 variable with the random intercept model with all level-1 and ...
1
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2answers
62 views

Survey weights at multiple levels

I am dealing with some data from a household travel survey, and I have a question about how to best use the survey weights that are provided. The structure is that households are sampled, and all ...
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0answers
31 views

How to interpret 3 main effects when an interaction exists for only two of the variables?

I've been searching for interpretation guidance regarding the below problem, but all the resources I've seen have been fully crossed (i.e., all variables included in the interaction term). Below is a ...
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0answers
132 views

What does “independent observations” mean?

I'm trying to understand what the assumption of independent observations means. Some definitions are 1 "the occurrence of one event doesn't change the probability for another". 2 "sampling of one ...
1
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0answers
18 views

Predicting dropout in an ordered process: Cox regression, autoregressive model, multilevel modeling?

I am working on a project in which I collected data about 100 people’s steps in an ordered process. All took at least one step, with some continuing up to a fourth step. Each person either drops out ...
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0answers
17 views

Feature/Variable selection to accompany mixed models?

I am trying to conduct an exploratory/data mining analysis to discover what socioeconomic factors best predict grade-school performance in children. I have a dataset with about 50000 ...
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0answers
13 views

In non-nested models, should group indicators have seperate mean for each?

I'm studying hierarchical model using Gelman & Hill book. On pg. 289, they discuss the following non-nested model. There's a psychological experiments of pilots, with $n= 40$ data point ...
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0answers
44 views

Mixed model with lmer: Variance of residuals should give the same as level 1 variance?

I expected that the variance of residuals from a mixed model computed by, for example, lmer should give the same as the residual variance from the summary output. ...
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0answers
13 views

Complex imperfectly crossed three level model - advice on data and analysis sought

I have a question about a multi-level model. I have data from three related sources. Data on about 30 hospitals, at hospital level - things like size, teaching/non-teaching and so on. Data from ...
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0answers
53 views

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 ...
2
votes
1answer
45 views

Random intercepts as response variables: Is there a name for this method?

I'm trying to find the name of this method (and ultimately a reference). The approach is as follows: 1) Fit a mixed-effect model with a random intercept $$ E(Y_{ij})= ...
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0answers
137 views

Identification of peer/neighborhood effects in a multilevel framework

My question concerns estimation of “peer effects“ or “neighborhood effects” in a multilevel framework. The idea of such an effect is that the behavior of a household (on level-1) is influenced by the ...
0
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1answer
94 views

Is it possible to construct a discrete-time multilevel hazard model in R?

I'm trying to run a discrete-time multilevel hazard analysis comparable to the model proposed by Barber et al. I am attempting to model the hazard of migrating internationally using predictors at the ...
0
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1answer
63 views

Estimating Multinomial Multilevel Logistic Models by Binomial models

I would like to fit a multinomial multilevel logistic Model. Unfortunately I couldn't find a package that implements this. I tried Stata's ...
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0answers
20 views

Multilevel - focus on higher level

I have a data structure similar to firms (the higher level) with individuals within them (the lower level). Each firm can have any number of individuals present. I have a reasonable set of predictors ...
0
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1answer
35 views

How to transform time-varying covariate measure of response time in a multi-level model of longitudinal data?

I am trying to fit a multi-level model to some longitudinal data that I have. As an example, let's pretend participants had to make 10 basketball free throws, and I measured how long it took them to ...
1
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1answer
64 views

Specifying variable levels in multilevel repeated measures in R using lme4

I am trying to analyze a dataset in which there are three measures on patients within areal units, however I am having trouble in how I am thinking about random/fixed effects and including covariates ...
3
votes
1answer
108 views

Specification of crossed random effects model in R

I have an experiment with a design in which subjects answer four items that are of four different types based on two factors (lets call the factors letter: "a" X "b" and big: "A" X "a", resulting in ...
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1answer
101 views

After trying various optimzers, model simplification running more iterations, when fitting GLMMs, R still produces warning messages

I am trying to fit GLMM's to my data using the glmer function available in R's lme4 package. The data is available at: https://onedrive.live.com/redir?resid=1B727FC7180E87DF%21118 I keep getting ...
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0answers
43 views

Answering Research Questions with Multi-level Structural Equation Modeling (ML-SEM)

This time, I have a more theoretical than computational predicament. I have a path model that I am interested in testing on a data set with two groups. It is a very simple two predictor model outlined ...
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0answers
70 views

Significance of variance components in Stata output

This might be trivial, but I'm used to HLM7 software output and now I'm switching to Stata (xtmixed). To give an example imagine I have students (level-1) nested ...