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7 views

“Overlapping” variables in partial correlation

Here is my problem: imagine I am studying the relationship between the frequency of swearwords in a book (per 1000 words) and the number of chapters in the book (I’m making this up – I’m really ...
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0answers
12 views

Are these models nested?

Are a standard Gaussian and a skew Gaussian nested? I'd say yes, because when we set the skewness parameter $\alpha=0$ in the skew normal we get the standard Gaussian. Also, are the normal/skew ...
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1answer
17 views

nested paired tests

I have a design with patients treated with a certain drug.We have patient data before and after taking drug.Within in these patients there is are two types of people , responders and non responders in ...
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0answers
23 views

Advice on ANOVA formula for nested random design

I have read "Design and Analysis of Experiments" 8th Edition by D.C. Montagomery. In Chapter 14, there is a nested experiment with two factor A and B. Both factors are random. Then the ANOVA test ...
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15 views

Hierarchical model with treatments nested in year

I am writing with what I hope will be a simple experimental design question. I have conducted a four year field experiment. During year 1, four treatment levels were applied (call them A, B, C, and ...
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1answer
98 views

Does the opposite of nested cross-validation make sense?

I'm asking the question from a machine learning point of view. I have a dataset with relatively high sparsity, so if I use nested cross-validation for my feature tuning and evaluation, that is tune ...
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1answer
35 views

positive price coefficient after instrumentation in demand estimation

I need to complete an assignment for Industrial Organization course where one of the tasks is to estimate a discrete choice demand model. This means I basically need to estimate a linear model: ...
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0answers
15 views

Why are results different from R mixed effect logistic regression models with nested random effects?

I have a dichotomous outcome on 2500 individuals. From 18 geographical areas, and many households nested within areas. I need to assess the association between various predictors and my outcome, ...
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1answer
38 views

Specifying a model with nested subsamples within split-plot design

I am trying to specify a model for split plot design that acknowledges nested sub-sampling. Split plot designs are a little bit tricky to analyze, and I am new to R, so I provide my dataset along with ...
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12 views

Interpretion of ANOVA with Nested Design

The following scenario is a basic nested design. I am trying to wrap my head around the interpretation of the ANOVA Table. Scenario: A school administrator is looking to investigate 5th grade ...
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1answer
74 views

Nested random effects and interaction terms in lme4

I have a data set containing various vegetation and geomorphic variables sampled in 3 distances on both sides of 43 drainage ...
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1answer
44 views

Nested linear mixed-effects model

I have 9 sites. Within each site, plant life was sampled to represent 70% of the basal area. Of the sampled plants, I know the corresponding family, genus, and species. For this project, I extracted ...
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39 views

Nested ANOVA with 3 random effects and unbalanced design

I would like to run a nested ANOVA to test three random effects (secteur, loc nested in secteur, site nested in loc) on the variable A. The design is unbalanced so I used lmer instead of aov. However, ...
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54 views

Comparing distributions from a factorial design

I have the following experimental design: I have six animals, where three received treatment and the other three were used as control (so treatment and control animals are not paired). From each of ...
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59 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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0answers
16 views

what is encompassing or nested models in forecasting?

I would like to ask what encompassing or nested models in forecasting means. I have a set of forecasts. A group of it is forecasted half hourly, so I have forecasts done a half an half an hour ago, ...
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2answers
40 views

R lm() nested formulas give different results

Online sources show two supposedly equivalent ways to write an R linear model formula with nested factors: ...
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2answers
107 views

How to compare nested factor levels to mean, not to first level, and how to test the last nested level in R lm()

I have two factors j (with 3 levels A, B, C) and k (with 3 levels M, N, O), with k nested within j. Level A of j is the reference level and it has only one k level, M, in it. What I want to test ...
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0answers
23 views

imbalance in sample size at multilevel longitudinal data

I have longitudinal data (BMI level) measured at 3 time points and subjects are students nested to schools. The sample size in school level differs considerably (n=85 % in school 1, n=10 % in school ...
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3answers
193 views

Is it advisable to drop certain levels of a categorical variable? [duplicate]

Let's say that I have one categorical variable with six levels, and I then create five indicator variables in order to represent the six levels. If two of the five variables are insignificant, then do ...
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1answer
38 views

How to correlate count variables that are nested / non-independent?

Above is a snapshot of a subset of a larger dataset, N=61. Group is the group number, Iterations is indicating the ...
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1answer
102 views

Comparison of log-likelihood of two non-nested models

I know I can only use the log-likelihoods of two models as selection criterion if they are nested. However, I don't understand this completely. Why isn't it possible to apply this reasoning to ...
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1answer
165 views

Implementation of nested cross-validation

I'm trying to figure out if my understanding of nested cross-validation is correct, therefore I wrote this toy example to see if I'm right: ...
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0answers
25 views

Fixed parameter estimates of parent factors in a nested design

Summary: What is happening with parameter estimates of factors that are the 'parents' of nested factors? Data: My analysis involves testing the effect of different parameter settings for automatic ...
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55 views

ANOVA P-value adjustments for semi-continuous data

In tests such as the Bonferroni post-hoc p-value adjustment test, convention is to correct the data with a constant, equivalent to the length (number) of pairwise comparisons that are being performed. ...
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1answer
15 views

fixed-effect nested factors in R with only SOME combinations present

I have a large data wth numerical response and two categorical factors: date and site. There are about 350 dates and 25 sites, but not all sites have observations on every single date (most have only ...
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0answers
23 views

lm with Nested factors with un-estimable levels combinations

I have a data with numerical response and two categorical variables: date and site. There are about 350 dates and about 25 sites, but NOT EACH COMBINATION OF DATES AND SITES is present (but there is ...
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23 views

post hoc nested

Hy, need to do post hoc test for nested factor in SAS. I have two factors, A and B with B nested within A and I want to perform post hoc test in GLM in SAS. Is it possible? Stevan
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0answers
37 views

nested multilevel model for differential expression analysis

I have read several other postings regarding nested models, but they did not seem to exactly capture my particular case, and I'm a bit unsure how to proceed with analysis of my model. Any help would ...
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0answers
28 views

Linear mixed model construction validation

I have 6 groups of fish made up of 8 individuals. Each group is tested three times under different treatments. These group level treatments are hungry , ...
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0answers
83 views

Using lmer for random effect and nested interpreting model comparison

I'm trying to do a lmer in r. I did an experiment in which I manipulated the temperature. My dataframe contains the following factors: Site: 11 level, random Species: 2 levels, fixed Subject: 10, ...
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42 views

Nested Anova for same group of participants

I am dealing with the following problem. I want to compare how some geometric measurements from the same participants can be connected with the existence of a disease. So the nested anova should like ...
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0answers
54 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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1answer
98 views

Nested data analysis using nlme: Analysis leaves out factor levels

Nested data analysis using nlme: Analysis leaves out factor levels I have a few questions regarding the analysis of nested data from an experiment. In the study, participants viewed 50 stimuli for 3 ...
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52 views

Regarding Nested Anova in R

I would just like to double check if my approach to the following analysis was correct. Based on my design I have two treatments (A and B) with treatment A being comprised of 5 populations and B of 3 ...
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67 views

standardization within time series and across groups (nested data)

I read through the previous threads concerning standardization of variables, but unfortunately have not found an answer whether it is justifiable or necessary to z-standardize values across groups ...
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1answer
287 views

Specifying Cross-Level Interactions in LMER

I am trying to figure out if it's okay to specify cross-level interactions in a hierarchical model with fixed effect predictor variables at both levels using the ...
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0answers
77 views

Correlations of fixed effects in logit mixed model with a nested fixed effect

I am using lme4 in R to fit a logistic mixed effects model of psycholinguistic data with three categorial (binary) fixed effects and two crossed random factors (subjects; items). The critical ...
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0answers
17 views

Age-at-event-stratified analysis for different case-control designs

My question is whether you can perform age-at-event-stratified analyses for: cumulative case-control studies (controls sampled at end-of-study) nested case-control studies (incidence density sampled ...
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0answers
11 views

Tree classifier or nested model?

I am new to statistics and was wondering what the right kind of model to use for the following scenario. I have two sets of continuous observations A and B for 50 samples. These 50 samples are ...
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1answer
196 views

Include nesting factor as fixed effect in a GLMM

I have the following GLMM: success ~ age + gender + group/task + (1 + group/task|school/subject), family = binomial I want to know whether participants' ...
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0answers
65 views

Triple nested cross validation

I have read several very informative posts including the link about the nested/double cross validation, which can determine (sub)optimal hyperparameter values as well as make an unbiased estimate of ...
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0answers
145 views

including interactions in a mixed linear model in R (lme)

I'm trying to test for the effect of soil moisture on transpiration rates. I have plot-level data for 18 plots in 6 different stands of trees (3 plots x 6 stands). I want to treat "stand" as a random ...
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0answers
36 views

Assessing the effect of related variables using lmer in R

I am trying to run a model to describe the rate of water table drawdown in the soil. The predicted variable is rate, and I am interested in the effect of two categorical variables: (1) if the water ...
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2answers
235 views

What is the right way to analyze a nested design in R?

I know that there are already a host of questions about nested designs but many of them haven't been answered or come from biological domains which I sometimes find hard to transfer to my domain. I ...
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0answers
246 views

Random Effects Tobit Model

I'm studying the effect of various criminal case and court district characteristics on sentence lengths. I was planning on running xttobit in Stata because I have individual defendants/cases within ...
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1answer
635 views

Nested ANOVA in SPSS / Science Education

I am analyzing student performance on a pre/post test designed to assess gains for a week long high school biology curriculum on natural selection. After comparing pre/post performance using a ...
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0answers
86 views

Unstable models, repeated crossvalidation, feature selection

I'm still trying to classify few (about 200) samples in a high dimensional feature space (dim=19) into 3 (very unbalanced) classes. I use an implementation of Least Squares SVM with one vs one coding ...
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0answers
60 views

Nested logit program in R

My question is specific to transportation modelling using a nested logit (NL) model. I wonder how to make a program including a t-parameter, t-value, and likelihood in R. I did estimation in a ...
3
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2answers
333 views

What to do AFTER nested cross-validation?

I've searched exhaustively on this forum and elsewhere, and have come across a lot of great material. However, I'm ultimately still confused. Here's a basic, concrete example of what I'd like to ...