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21 views

Power calculations in R [duplicate]

I need to use R code to calculate the power of a Nested ANOVA. I want to detect a 3% difference between two consecutive tests between a stage in a process. The tests are identical and material has ...
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0answers
6 views

When nesting within two factors must the GLM contain their interaction?

I am running a general linear model with repeated measures - individual is a random factor, which should be nested within both treatment and family (also random). In the past, my statistics package ...
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0answers
18 views

Cox Time Series Data — Analysis of Interaction Terms

In a time series data set using Cox Proporational Hazard Rate, I am testing a model with interaction terms. I am worried that my interaction term is biased by several specifications of my model and I ...
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1answer
16 views

How to derive formula for marginal probability of choosing nest in nested logit model?

I am trying to understand all the details of the nested logit and what confuses me is the formula for marginal probability of choosing the nest. In more details: the joint probability of individual n ...
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0answers
16 views

Repeated measures mixed model with nested data

I have been trying to figure out how to run the stats I need for this study for weeks and despite reading endless amounts of information am not much the wiser! If anyone can help, I would be hugely ...
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1answer
23 views

Dependent questions in SPSS [closed]

I have questions in a survey that are dependent on other questions, i.e. nested questions. How do I enter those into SPSS? Example: ...
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1answer
18 views

Repeatability estimation using a mixed model with repeated measures by four raters

I am a medical doctor and definitely not an expert in statistics, although I think I do okay and I am familiar with R. I have discussed the following issue with a statistician but I am still not sure ...
3
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1answer
90 views

Repeated-measures linear mixed effect model

I have used a repeated-measures ANOVA in SPSS to analyse some of my data. It's the typical approach in my area, but I think it might be more appropriate to use a mixed effect model. However, I ...
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0answers
28 views

Stata nlogit and nlogitrum for the nested logit model.

In stata 12, do nlogit and nlogitrum estimate the same model. I understand before stata 10, nlogit estimates the non-normalized nested logit. That one is not consistent with utility maximization . In ...
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0answers
13 views

What will be the best test to determine the significance in this study?

The project does not have a simple design. It is planned as follows: It is a longitudinal observation during 120 days in 48 subjects (with repeated measures using multiple tests); The subjects were ...
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0answers
8 views

Nested ANOVA for species, genera, etc in R

I am wondering how to set up a nested ANOVA in R that will show me whether the greatest variance in genome size is found at the order, family, etc. level. My data would be in columns with the ...
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0answers
20 views

Weighted nls fit of multiple datasets with nested paramaters

I have a number of datasets that I'd like to fit with a model of the form a*(x+b)^c where b, c are common to each dataset with only the amplitude changing. I currently have this working in r, but I ...
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0answers
22 views

How to define random effects for nested LMM

I investigated the behaviour of 125 individuals in 25 groups of 5 individuals across 4 days. The data is structured as follows (only showing 2 dummy groups and 2 individuals in each group): ...
3
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1answer
28 views

The valid variance components to include in a generalizability theory model (anova) involving nesting? Are these correct interactions?

My question is about generalizability theory. A study by Bergeron, Floyd, McCormack, and Farmer (2008) is only adding to this confusion. Basically, in G-theory you want the first model you run to ...
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0answers
26 views

Correlation between categorical and numerical variable, controlling for a third “overlapping” numerical variable

I am interested in the relationship between a numerical variable (let's call it density) and a categorical binary predictor (let's call it class), controlling for two other numerical variables (length ...
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0answers
14 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
23 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
31 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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0answers
17 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
106 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
55 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
17 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, ...
0
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1answer
50 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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18 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
102 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 ...
3
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1answer
54 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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0answers
72 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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0answers
60 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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0answers
98 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
60 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
178 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
28 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
216 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
67 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 ...
3
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1answer
152 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
270 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
33 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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0answers
63 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
21 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
32 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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0answers
27 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
40 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
32 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
91 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, ...
0
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0answers
63 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
67 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 ...
0
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1answer
111 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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0answers
65 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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0answers
97 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 ...