The tag has no wiki summary.

learn more… | top users | synonyms

1
vote
1answer
27 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 ...
2
votes
1answer
55 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 ...
0
votes
1answer
58 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: ...
3
votes
0answers
14 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 ...
2
votes
0answers
38 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. ...
0
votes
1answer
10 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 ...
0
votes
0answers
7 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 ...
0
votes
0answers
13 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
1
vote
0answers
35 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 ...
2
votes
0answers
24 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 , ...
0
votes
0answers
58 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
votes
0answers
21 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 ...
1
vote
0answers
45 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
votes
1answer
64 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 ...
0
votes
0answers
41 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 ...
0
votes
0answers
35 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 ...
1
vote
1answer
172 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 ...
0
votes
0answers
56 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 ...
0
votes
0answers
15 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 ...
0
votes
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 ...
1
vote
1answer
134 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' ...
0
votes
0answers
56 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 ...
1
vote
0answers
115 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 ...
0
votes
0answers
28 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 ...
2
votes
2answers
153 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 ...
2
votes
0answers
184 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 ...
1
vote
1answer
288 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
67 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
53 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
204 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
318 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
68 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
votes
0answers
44 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
votes
0answers
41 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
votes
0answers
71 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
votes
2answers
1k views
0
votes
0answers
118 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 ...
5
votes
1answer
224 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
votes
0answers
62 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
36 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
102 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
69 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
26 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, ...
5
votes
1answer
236 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
vote
0answers
204 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
23 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
19 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. ...
1
vote
0answers
32 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
vote
0answers
118 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
104 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 ...