# All Questions

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### Are these two estimated regression coefficient asymptotically equivalent? If not, which one is more efficient?

Suppose I have $Y=\beta_1X_1+\beta_2X_1X_2+g(X_2)+u$, where $E(u|X_1,X_2)=0$ and $S=g(X_2)+e$ with $E(e|X_2)=0$. I have a random sample $\{Y_i,X_{1i},X_{2i},S_i\}_{i=1}^n$. Suppose I first use a ...
43 views

### Can logistic regression predictor variables be nominal?

Can logistic regression predictor variables be nominal (like the charlson comorbidity index which ranges from 0-6)?
1 vote
44 views

### Can I estimate the mean of a dataset if I have its standard deviation and a portion of the full data that is higher than some threshold?

I have a partial set of measurement data that is limited due to my tool's sensitivity. I know that the data is approximately normally distributed and I have a standard deviation from another data set ...
1 vote
41 views

### Sample Size Calculation for Gene and Protein Biomarker Study

The PIs are looking for biomarkers in pre and post-trauma individuals. I need to calculate a sample size for a microarray study of 10 genes and the top 5 up- and down-regulated proteins and ...
20 views

### compare the outcome of logistic regression (predictive probabilities) before and after an event

To train a glm model, I'm using using clinical data (~10 features) of a large cohort of patients and healthy subjects. I'm using a smaller test group (around 20 people) and predict their outcome (...
25 views

### AR(n) process error variance in R

I was wondering where does the "sigma^2 estimated as 12.2" in the following example came from. I tried to compute by myself the variance of the residuals, however it seems I probably forgot ...
6 views

### Alternatives to partial mantel test for removing spatial autocorrelation in R?

I have a presence/absence distance matrix based on eDNA sampling for certain species at ~30 sites. I would like to see if the volume of water filtered influences species detection, accounting for the ...
5 views

### Multi-level meta: do I include a measure of precision in subgroup analysis model?

In a meta-regression model, a precision measure (SE or SE^2) is often included in the model along with covariates. Is the same true for subgroup analysis in a multi-level analysis wherein moderators ...
10 views

### Significance test to compare groups when a variable has multiple occurences per case

I'm finishing a manuscript, but have one nagging problem which I'm unable to find an answer. Study has two groups which receive different procedure for a disease. After the procedure, one patient may ...
10 views

### Modeling a chargeback rate as a function of an approval rate

I am working on a problem where I would like to estimate chargeback rates for online goods orders as a function of the proportion of orders that are approved (approval rate). The approval rate is a ...
5 views

### Is it appropriate to conduct a Kruskal-Wallis test with the mean of a 3 item construct measured on a 7-point Likert scale as independent variable?

I am working on my master's thesis and conducted two studies. The first study utilizes 3 groups. The problem is, that the group sizes are very small (n1 = 13, n2 = 14, n3 = 14). I want to test if ...
12 views

### Understanding parameters interaction contrasts in model averaging

I am struggling to understand how parameter interaction contrasts play into model averaging. As I am new to Stack Exchange, I apologize if my question is in the wrong place or incorrectly asked. I ...
1 vote
18 views

### Significance test of an increase in adjusted R-squared between two models

I found two papers that provide their results showing the significance of an increase in adjusted R-squared between two models statistically, with p-values, to show the improvement after adding a few ...
23 views

### Does Maxwell–Boltzmann distribution belong to exponential family? [closed]

PDF - $\sqrt{\frac{2}{\pi}} \, \frac{x^2}{a^3} \, \exp\left(\frac{-x^2}{2a^2} \right)$ If yes - provide an estimator and parametric function ($T(X)$ and $\tau(a)$)
1 vote
40 views

### Summary from lme() output returning estimate value of 0?

I'm trying to run a linear mixed effects model using the nlme package using the lme() function with the txhousing data from the <...
1 vote
25 views

### Applying a non-linear model to assess the difference between variables [duplicate]

I have already asked a similar question on this site (Correlating two variables / convergence); however, I feel like the way I wrote the previous one made it a bit too ambiguous, and on top of that, ...
1 vote
46 views

### Matching order based on grouping variable

I want to match in a certain order. I am aware of the argument order, available in package {MatchIt} - but this refers to the ...
11 views

### Reliability and repeatability [closed]

Which is the difference between reliability and repeatability and which test can use available in Jamovi?
44 views

### Regarding samples gotten from MCMC

In one article explaining MCMC, I once read the following statement. The idea of sampling methods is the following. Let’s assume first that we have a way (MCMC) to draw samples from a probability ...
10 views

### Why the F test is NA in R package Fect?

I am a new learner of Fect package in R, see https://yiqingxu.org/packages/fect/fect.html. I try to use method to do counterfactual analysis of my DiD. I use unbalanced panel data, and the Matrix ...
14 views

### What embeddings are used in decoder-only models like GPT?

Decoder-only models do not use an encoder. Hence, they do not get the embedding from it. I went through this nice description of a decoder-only transformer -based model I do understand the training ...
55 views

15 views

### Mediation analysis - Hayes Process plugin

I have a model to test 4 hypothesis (all data was collected on a 5-point likert scale through surveys): Ability (IV) has a positive relationship with PO fit (M) PO fit (M) has a negative ...
37 views

### What model could be the best for this problem?

I would like to know which model could be the best for the problem i have: I have data at baseline, at 3 months Follow-up, and data until 2 years of follow up. I have classified individuals as if they ...
17 views

### To create a vector from a vector in R software [closed]

I am new to R language. Suppose I have a vector v<-c(1,6,7,4,6,9,20,15.....) I want to create another vector c from this vector whose elements are suppose for example:-1st,4th,7th,10th,13th and so ...
46 views

### Interpreting intercept with centered predictors in logistic mixed model

I am running a logistic mixed model in lme4. The model is as follows ...