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2
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2answers
57 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 ...
0
votes
0answers
11 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 ...
1
vote
0answers
24 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 ...
0
votes
0answers
39 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
votes
2answers
84 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 ...
1
vote
1answer
69 views

Random factor nested in two fixed factors

I have read Random effect nested under fixed effect model in R, but I have a doubt: My data is on germling survivorship, I have Temperature as a fixed factor (2 ...
0
votes
0answers
24 views

MIXED modeling of 2 within-subject factors with 2 repeated factors and df

This is a novice question regarding MIXED models, denominator freedom degree, and long format (e.g., in SPSS). Most Mixed Model tutorials that I find address between factors and repeated measurments. ...
0
votes
0answers
24 views

Including nested random effect in a GAM

We have 6 transects at 6 different sites (6 transects per site). Each site subdivided into two zones therefore in our model we have: Site (fixed categorical factor) and Zone (random categorical factor ...
0
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0answers
30 views

Can all the p-values from drop1 models be high even when the p-value for the full lm model is low

I have used the R lm() function to fit a model with one numeric and ten categorical variables. The p-value reported for the regression is very low: Residual standard error: 2.459 on 320 degrees of ...
2
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0answers
35 views

Data Mining Methods with Nested Data

I have three general questions that I am really struggling to answer: a) When we have nested data (e.g. employees nested in departments which are nested in companies which are in specific ...
0
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0answers
39 views

question about multi-level modelling with nested data (R/Stata/SPSS)

I have a dataset composed of observations taken from 16 separate experimental panels, each nested into one of 4 conditions (Treatment A Level 1, Treatment A Level 2, Treatment B Level 1, Treatment B ...
0
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2answers
222 views
0
votes
0answers
54 views

Mixed model, repeated measures, nested?, nominal data

I am not sure how to approach the statistical analysis of the following study. Any insights would be greatly appreciated. Thanks! So, I have two independent groups, group A and group B. I am ...
2
votes
0answers
70 views

Nested ANOVA: Unequal sample sizes? Variance components?

I am completely out of my depth on this, and all the reading I try to do just confuses me. I'm hoping you can explain things to me in a way that makes sense. (As always seems to be the case, "It ...
0
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0answers
33 views

Poisson Regression Nested Design

At the moment, I'm trying to do a 'Poisson Regression'. I have several years (2004 to 2012) with four seasons in each year. My dataset consists of the amount of carcasses found every 10 days, and the ...
0
votes
0answers
19 views

Nested Design, Split-plot or ANOVA

I have general statistical question concerning the analysis of two-factorial experiments. I would like to compare several response variables (biovolume, richness etc.) of two experiments (homogeneous ...
0
votes
0answers
43 views

Including a nested factor as random effect in a GLMM

Good afternoon, I'd like to ask for advice on including a nested factor as a random effect in a GLMM. I've read other threads in this forum, but still am not able to answer my question. Any help is ...
1
vote
1answer
28 views

Is a model nested within itself before collapsing categorical variables?

If I have a model with a categorical variable $X_1=\{0,1,2,3\}$ and a continuous variable $X_2$, and I have a regression model that includes an interaction between $X_1$ and $X_2$, then I decide I ...
0
votes
0answers
13 views

How do I test for equal variances in a nested design?

I've got a dataset where stations (3) are nested within beaches (5). Every station is replicated 6 times per beach, so that I have a total of 90 observations. I now want to test for equal variances, ...
4
votes
1answer
122 views

Linear regression - are my models nested or non-nested?

I’ve got two main groups, which I am comparing, a) rats and b) rabbits. Each group consists of two subgroups – breed 1 and breed 2. Using linear regression, I would need to find out, does a model ...
1
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0answers
81 views

Fixed, random effect and nested factor in lme

I have a dataset with the following variables: Treatment : (fixed,3 levels) Location : (fixed, 4 levels) Sample (random, 5 levels): 5 samples are taken in each location (randomly) Subsample ...
3
votes
0answers
20 views

How to analyze data with a lot of missing data (including covariate, nesting and blocking)

I have data set that was haphazardly collected to test grazing impact on soil. To test the grazing impact, 6 replicate soil samples were collected from inside a fence and 6 replicates were from ...
0
votes
1answer
15 views

SVMs for nested/prioritzed text document classes.

Let's say A, B, C, D, E, F are classes of text documents (i.e. sentences). Usually they occur distinctively, say: one document is precisely C. But sometimes one document is C AND A, at the same time. ...
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0answers
26 views

Need help with proper syntax for SPSS Mixed [closed]

I am having trouble building my model properly, and I was hoping I could get some advice here. I have a 2 (S: P vs. D) x 3 (ET: CA vs. CO vs. AD) between-subjects design. Participants were run in ...
1
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0answers
52 views

Very Low ICC in HLM

I ran a HLM analysis (One Way ANOVA with random effects model). I calculated my ICC and it is very small (00.1%). I understand this means that there is basically no meaningful level-2 variability in ...
0
votes
0answers
63 views

Mixed model regression with non-independent (nested?) data in r

I am having trouble modeling a regression with seemingly non-independent, nested observations. I am examining the effect of relatedness on proportion of offspring in cases of multiple males ...
0
votes
1answer
64 views

Nested design with pairing

I have been asked to help a colleague with analysing the following experimental design. 2 treatments (fixed), 5 time points (fixed) with 4 animals (random) at each time point. The animals within each ...
1
vote
0answers
25 views

How do you control FWER when testing multiple nested models with likelihood ratio tests?

Suppose I have three different models $M_1, M_2$ and $M_3$, these models are nested such that $M_1 \subseteq M_2 \subseteq M_3$. I perform two likelihood ratio tests, $M_1$ against $M_3$ and $M_2$ ...
0
votes
0answers
99 views

Dealing with nested factors and correlation structure in a GEE model

This question is of a previous one that has not been answered yet (see the details of our experiment and question here). We are now exploring a GEE (Generalized estimating equation) approach that ...
0
votes
0answers
33 views

How to analyse spatially and temporally dependent data?

I would be very grateful if anybody has some suggestion about how to deal with the statistics of the following experiment. I am planning to study soil characteristics under different trees in soil of ...
0
votes
0answers
20 views

Compare variance and point statistics in a 3 way group

I need some help on this analysis. I have 3 groups of individuals, different the level and kind of physical activity. For each individual I have the heart rate, taken every minute for ~24h. (each ...
1
vote
0answers
72 views

Nested Anova Question:

I've a dataset for measurement of protein marker abundance for two groups of individuals, Treatment and Control. Within these two groups there are several subjects and for each subject there are three ...
4
votes
1answer
141 views

GLMM model specification help gender effects + an effect that is nested only within female

Main question: "What are the contributing variates to daily movement distances?" Specifically my question today relates to: "What is the contribution related to gender, and then within female what ...
0
votes
0answers
50 views

What to use: Nested Case-Control or Case-Cohort?

I am following a cohort of patients over time from which I am planning to sub-sample a sub-group of patients to pilot a new intervention. The plan is to compare the effectiveness of the new ...
0
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0answers
57 views

Why variances from nested random effects appear identical?

Could anyone shed some light on a slightly confusing result from a lmer4 model in R? I have a nested random effect, but the variance explained by each level seems identical, and I can't see why. I ...
3
votes
1answer
136 views

The test statistic in the likelihood ratio test for nested linear models

Imagine that we have a family of probability disributions with p.d.f $f_{\theta}(z)$ where $\theta \in \Theta$. We also know that there is a linear dependence between parameters. As a consequence we ...
0
votes
0answers
88 views

nested design after anova tukey

so I analyzed a nested design (split-plo, 2x4 factorial) with ANOVA and it indicated that there are differences in the levels of factor b. I went on with t-tests comparing the means depending on ...
6
votes
1answer
261 views

Why can't likelihood ratio tests be used for non-nested models?

More specifically, why do the likelihood ratio tests have asymptotically a $\chi^2$ distribution if the models are nested, but this is no longer the case for the not-nested models? I understand that ...
2
votes
1answer
256 views

Using AIC to select between models that use nested and non-nested variables

I'm using SPSS to try and find a mixed model that adequate explains the data that I have. Two of the explanatory variables are closely related ('Sample group' and 'individual'), as an individual is ...
0
votes
1answer
140 views

From dummy coding to ordinal variable

I have read from multiple sources (like this pdf) that in a linear regression model, an ordinal variable can be obtained by imposing linear restrictions on its dummy coding. e.g. $x$ is an ordinal ...
0
votes
0answers
102 views

GLM with quasipoisson nested distribution

I want to make a GLM with a quasipoisson response distribution. My response variable is inflorescences by plant and my explanatory variable is coverage. For inflorescence counts, I used the average ...
1
vote
1answer
926 views

Structuring a linear mixed model in R with nesting

My ecological question is: "What are the trends in percent coral cover by island and depth across the state of Hawaii from 1999 to 2012?" I am trying to analyze this hierarchical data set using R ...
2
votes
0answers
60 views

Is this a nested model?

I have a dataset with explanatory variable $X$ and response variable $Y$. Besides, there is a two-level factor $S_{j}, j=1,2$. The random error variance might be different between these two strata. I ...
2
votes
1answer
141 views

Is this a nested model and can I use the likelihood ratio test?

I have a data set, total_data and I applied a model to it. For instance, the model has one parameter $\beta$, and I calculated the log-likelihood of the fitted model (using maximum likelihood method). ...
1
vote
0answers
408 views

Nested Logit model in r

I am trying to run a nested logit using mlogit in R to analyze data from choices people made. There are 4 possible alternatives they could choose from, but in any given choice situation a person had ...
1
vote
0answers
117 views

Nested test to remedy pseudoreplication

Data structure: I have two datasets from two protected areas that differ in protection status. Both areas contain 43 and 37 sites each. Question: I would like to know which test would be the best ...
1
vote
1answer
570 views

How do I set up a multivariate hierarchical multiple linear regression in R?

I have two continuous DVs (measurements taken on individual fish), one continuous individual level IV (fish's size), and two site-level IVs (PC1 and PC4). Sites are either take or no take. There are ...
2
votes
1answer
77 views

Nested Models for Likelihood Test

If I have a logistic regression model with 3 predictors, $x_1$, $x_2$, $x_3$, and then I remove $x_3$ from my model (left with only $x_1$ and $x_2$), are those models nested? And therefore I can use ...
0
votes
2answers
296 views

One-way repeated measures anova

I tried finding an answer to this question on this and other sites but to no avail - if I am missing something please excuse my inability to locate the answer! Basically I have several dependent ...
1
vote
0answers
295 views

Mixed model repeated measures, nested

I have a study in which I have 3 groups of crews (4 crews in each group) in which there are two people (L/R). Each crew experienced 4 lighting treatments (D1-4), once in one position, and again in ...