# All Questions

137,827 questions
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### Interpretation of a brier score

Suppose that multiple brier scores were computed for two models $A,B$ and the density of the scores plotted as Where the average of $A$ is less than $B$ What would the interpretation of this be? ...
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### Determining Conditional Independence from Marginal Independence?

so if I have a 3 columns of binary variables X, Y and Z with their respective values and I would like to determine whether X,Y are conditionally independent given Z. How can I go about doing this? ...
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### When asked to run a GLM for main effects and two-way interactions, what exactly does two-way interactions refer to? [on hold]

So just looking for clarification on a HW question, want to make sure in doing the right thing. The two-way interactions refers to adding the extra "multiplied" variables in, right? So if the two ...
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### Panel model and the multivariate model

Can I apply the Panel model to a multivariate model with six dependent variables and one independent variable
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### Common data processing mistakes which have huge impact on further analysis [on hold]

I recently made a mistake of not treating special values of Bureau credit scores while predicting default in an analysis. This led to counter-intuitive trends being observed. Can you share some ...
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### What is a good name for a density function that does not relate to probability?

There is confusion between normalized functions whose area under the curve is one, i.e., density functions, and probability density functions that are not only density functions but that are measures ...
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### Why is lasso more robust to outliers compared to ridge?

In my attempt to reason about it intuitively I am concluding that ridge might be more robust to outliers. Following is my intuitive/lose reasoning : If there is an outlier then to match my ...
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### Two-way mixed ANOVA - do I need to transform pretest AND posttest

I am conducting a two-way mixed ANOVA on intervention data from a randomized controlled trial (i.e., my within-subject factor is time, and my between-subject factor is treatment condition). My ...
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### Power spectral density attenuation confidence interval

I am trying to compare power spectral density (PSD) estimates of two stochastic signals. I compute the attenuation by dividing one PSD by the other (both PSDs are computed and smoothed within the same ...
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### How would I model underlying probabilities of failure with this data?

I have a dataset with measurements of a machine taken at different timepoints. I'm assuming at every timestep, the underlying state of the machine is a number between 0 and 1, where 1 indicates the ...
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### Feature engineering for sheet music

I have a large dataset of digitized music scores that I'd like to use as input to a network. Initially, I'm looking to train networks to identify key signatures, tempo, dynamics, etc. from the raw ...
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### Naive bayes computation of denominator

I'm wondering about the denominator in this computation : ...
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### Is my data inappropriate for a zero-inflated regression model?

I am working with count data where I have an abundance of zeros for one of my categorical factors (Day). I have generated two models, p1 and m1, with zeroinfl() and ...
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### Do GGMs model partial correlation or conditional independence or both?

Post that says partial correlation != conditional dependence/independence: https://www.quora.com/Does-a-partial-correlation-of-0-imply-conditional-independence Post above points to following paper: ...
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### How to transform my data appropriately? [on hold]

When I did time series analysis and plot the time series plot, the plot shows non-constant variance. How can I process it if the plot like this.
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### Unbiased Estimator of the Standard Deviation of the Sample Standard Deviation

I'm looking for an unbiased estimator of the standard deviation $\text{SD}(s)$ of the sample standard deviation $s = \sqrt{\frac{1}{n-1} \sum_{i=1}^{n} (x_i - \overline{x})^2}$. I have found this ...
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### Combining classifiers built on different features

I have a binary classification problem and two sets of features(for the same target variable) . Due to some reason(domain knowledge), I can't combine those two feature sets into one and then do ...
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### Why we need to do bootstraping and extract confidence interval for classification problems?

My question is related to bootstraping and extracting confidence interval for classification problems. Let's say I have 25 number of data points and 2 features and use Gradient Boosting Machine (GBM) ...
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### Can Ordered Logistic Regression be used for tally/sum scores?

Suppose I have 6 vignettes and the possible responses to all those vignettes are 1 (YES) or 0 (NO). If participants answered (YES) to all six vignettes, they would get a tally score of 6. If they ...
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### Improve precision/recall for class imbalance?

Trying to get better precision/recall for both classes ... any tips? I have heterogeneous features [a few num vars, a few cat vars, and 2 text vars] Target is a binary classification w/ class ...
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### Fractional un-differencing of time-series

I have time series y that has long-memory 0 < d < 1. I have differenced y with order d, resulting into y'. I would like to now restore y' back into y. Do you guys know how to do that? P.S. ...
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### Appropriateness of nonparametric bootstrap methods to assess difference between two groups

This question is motivated by the discussion of this earlier question. I have two samples $X$ and $Y$, where both samples have $n$ elements. Both samples represent optimal solutions returned from two ...
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### PCA whitened data

Let $X$ be a feature matrix of size $m\times d$. I understand that the standard PCA whitening process follows three steps. (Centerization) ${X} \to \hat{X}:=({X} - \mu)$, where $\mu$ is a matrix of ...
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### undersampling before or after cross-validation

I have a classification problem with highly unbalanced classes. In 4000 samples, 1% is 1s and 99% is 0s. Normally, I would use the balance technique only in the training set. However, I expect that ...
23 views