All Questions

138,957 questions
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Including the outcome variable in multiple imputation

I'm trying to perform binary classification on a dataset with missing values. I used sklearn's iterative imputer to impute these values and I got pretty good results. However, I realized that I was ...
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I have a set of enrollment percentages for every major ethnic group for a study I conducted about a disease I'm interested in. I have the age-adjusted annual incidence rates for that disease, for each ...
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In what situations would it be appropriate to use Ridge Regression vs Multiple Regression and vice versa?

My understanding is that regularization will generally help prediction tasks. What about for situations where we want to conduct a study to understand the effect of a specific predictor on the ...
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How to interpret the tests for weak instrument in R?

Stock & Yogo (2005) provide the rule-of-thumb that the first-stage F-test of an IV regression should be above 10 for the bias of the instrument to be less than 10%, and suggest to call weak an ...
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What type of accuracy should I reported in research paper?

I have read some research papers on the classification task of deep learning, and now I am doing my own. After investigating some research paper which also provided the source code for reproducing ...
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Machine learning for discrete probability distributions when events can be rare

I am following a paper which suggests using a restricted Boltzmann machine for learning a discrete probability distribution. I have encountered a problem, however, when the scientifically "interesting"...
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glmm (poisson or negative binomial) which explain the significance of each single level

I'm using the function glmer.nb of the library MASS to analyse the effects of two fixed factors (temperature: 2 levels and salinity:3 levels) and nested random factor (Individual ID/room) on parasite ...
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Can bagging outperform a random forest?

I want to predict wages and constructed bagged regression tree's and a random forest of regression Tree's. The bagged regression tree's outperform the random forest. Is this result even possible , I ...
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Robust two-sample test with triplicate measurements?

When testing for a difference in mean between two conditions, biologists typically use a $t$-test, and wring their hands endlessly about how to justify removing outliers. Whereas I typically use a ...
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Oversampling in Uplift Modelling

I hope any of you can help me in the following matter: I am about to write my master thesis addressing the question how response and uplift modelling differ in terms of performance but also the ...
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How can I do t.test when I don't have a null value?

I have a dataset containing 20,000 records of home sales. I'm asked Choose a numerical variable from your dataset. 1. Calculate a 98% confidence interval for the mean of this variable. I chose the ...
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significance of difference smooths

I am working to understand what is represented by the standard errors and confidence intervals of smooths of ordered factors. In this toy example, I wish to determine (1) the overall form of the trend ...
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GAN: Why can't we just use leakyRELU for discrete data to overcome vanishing gradient descent?

If we use a leakyRELU activation in the last layer of the generator of a generative adversarial network vanishing gradient descent won't be a problem at all in my opinion? But no one really mentions ...
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Which study design of R survey package to use with NAMCS dataset?

From official dataset documentation: ...
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Naming of mathematical elements in GMM?

I'm struggling with the naming of different elements in GMM. There doesn't seem to be consistency in the literature. What do we even call the moment integrand $g$? I take a stab below with help from ...
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Regarding interpretation of Odds Ratio

I have just read in my professor's lecture notes that the Odds ratio $\psi(x)$ takes non-negative values, and that the the effect of $X$ (the predictor) on $Y$ (the binary target variable) is measured ...
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Perpendicularity of random variables?

I am reading Bechavod et al. (2017) [1], and at page 3 there is written: In the example, each data point lies in $X = (X_1,X_2) = \{0, 1\}^2$ and has two features—$X_1 = A$ is the protected ...
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Can I say that the Factor, on factor analysis is the eingenvalue of the covariance matrix? [on hold]

Can I say that the Factor, on factor analysis is the eingenvalue of the covariance matrix ?
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What does it mean to have “groups” and “levels” of variables?

Using this website, a user can find a correct statistical test for their project. However, what do they mean when they write "2+ groups" or "2+ levels"?
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Identifying the difference between distribution when d > 1

Lets say I am measuring the velocity of wind at every 500m road segment (x) at time (t) on the Interstate 5. I classify each measurement into three clusters (...
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Do finite mixtures of normals have heavier tails than normal? [on hold]

Consider a finite mixture of normals $$f(x;\mu_1,\dots,\mu_n, \sigma_1,\dots,\sigma_n) = \sum_{i=1}^n \omega_i \phi(x;\mu_i,\sigma_i),$$ where $\sum_{i=1}^n \omega_i = 1$ and $\phi(x;\mu_i,\sigma_i)$...
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training a nn with f1 as loss on keras doesn't work?

I have no problem to train my neural network with categorical_crossentropy as loss but when I do the same with f1, it just doesn't progress : Epoch 1/9 1029/1029 [==============================] - ...
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Why ivmodelFormula and ivmodel give different results in R?

I stumbled upon an issue with the ivmodel package: when exogenous covariates are included in the model, the ivmodel function ...
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Multivariate regression for dataset with several dependent variables?

I'm looking at whether bottle size, design etc. has an effect on perceived value, perceived quality etc. So first set are the independent variables and the second are dependent variables. Would ...
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SEM: issue with two correlated latent variables

I am fitting a SEM model that includes socio-economic status (SES) for a household and environmental conditions (env) surrounding this household (road condition, sanitation etc). My (obvious) ...
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Is it possible to statistically compare the factor loadings or canonical coefficients coming from a canonical correlation analysis run within each of two groups across both groups? e.g. statistically ...
11 views

Generalized estimation equation distribution and link

Please fill me in. Thank you in advance. I have 3 response variables, 2 of them are positively skewed and have a continuous positive value while the rest is negatively skewed and have a continuous ...
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Empirial Bayes for means

I have data for US ~3100 counties where the variable is a mean score based on a sample. However, for many small counties, the sample size is quite small (like 5), and so these mean values fluctuate a ...
19 views

In CNN, how to map from fully connected layer to output image?

In CNN, where the last layers are fully connected, how to make pixel-wise prediction to output an image(binary matrix), if the number of neurons in the last layer is less than the size of the image?
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Regression and Covariance Parameter Matrices in Multiresponse Gaussian Regression Using glmnet (R)?

I am new to using glmnet. How do you extract the estimated (sparse) regression and covariance parameter matrices in multiresponse gaussian regression using the glmnet package? There doesn't seem to be ...
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Using sigmoid in binary DNN output layer instead of softmax?

For a binary DNN, the output is $y_0 + y_1 = 1$ since they are the probability distribution, hence the sum must equate to 1. However, I've been told that $y_1$ is sufficient to represent the output of ...
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Mean and variance of $\tan^{-1}(\mathcal{N}(\mu,\,\sigma^{2}))$

How could we find the mean and variance of $\tan^{-1}(X )$ if $X \sim \mathcal{N}(\mu,\,\sigma^{2})$?
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Limiting number of independent variables in data before running linear regression [on hold]

I'm working with this dataset: https://www.kaggle.com/c/house-prices-advanced-regression-techniques/data and would like to use it to conduct linear regression (and maybe also Lasso or Ridge). After ...
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Interpretation of r and r squared in reduced major axis graph [on hold]

I have a correlation test where i used reduced major axis to get r and r squared, I am not sure though which value i should use for interpretation of the graph and what the difference is, because ...
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Sufficient Statistic and Unbiased Estimate in Exponential Family

I am reading this classic paper (Information and the Accuracy Attainable in the Estimation of Statistical Parameters) by CR Rao where he deals with sufficient statistics in exponential distributions ...
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Can Random Forests deal with variables that affect eachother?

I'm studying temporal aspects of a decision-related brain process. For this study I want to see how much the information (absolute amount of contrast and/or amplitude) of a stimulus at different time ...
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Identification of changing scope as formative constructs? [on hold]

Can scope creep/ requirement creep be evaluated as formative constructs?
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Factor Analysis PCA - Interpreting SPSS Pattern & Structure Matrix

I conducted a Factor Analysis using SPSS (see output attached). I used an oblique rotation (direct oblimin). How do I tell which variables load most highly on each factor?
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