# All Questions

0answers
39 views
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### Statistical method to test if a set of values is similar to a group of known similar sets of values

I am not sure if this is to be asked here - I am working and interpreting data related to certain events. I noticed that a particular subset of values always seem to match events which is of ...
0answers
71 views
+200

### Assessments of “Approximately Normal” for t-tests

I am testing equality of means using Welch's t-test. The underlying distribution is far from normal (more skewed than the example in a related discussion here). I can obtain more data but would like ...
1answer
126 views
+250

### Clustering — Intuition behind Kleinberg's Impossibility Theorem

I've been thinking about writing a blog post on this interesting analysis by Kleinberg (2002) that explores the difficulty of clustering. Kleinberg outlines three seemingly intuitive desiderata for a ...
0answers
25 views
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### Quantile aggregation for a sum of dependent variables

I am currently working with a sum of dependent variables following complex laws. For these laws I have a vector of means, $\mu$ and a linear correlation matrix $\Sigma = \rho_{i,j})_{i=1..n,j=1..n}$. ...
1answer
94 views
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### How to perform ANOVA followed by a post-hoc for model comparison?

My data is the measurement of 4 type of samples with three different methods where I want to see the interaction and main effect, compare them from each other. The data look like as follows: ...
1answer
52 views
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### Introduction to Markov Process (Part 2): Dynamical system and Markov relationship?

In my previous post asked here Introduction to Markov process: How to prove that a process is Markov? Part 1, -- a process is Markovian if it follows the memoryless property. Consider, a dynamical ...
1answer
581 views
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### Ratios of means - statistical comparison test using Fieller's theorem?

I would really appreciate any suggestions with the following data analysis issue. Please read till the end as the problem at first may appear trivial, but after much researching, I assure you it is ...
1answer
41 views
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### Comparing individual predictions across two models

I want to find patterns in the way that two models, Model A and Model B, perform on my dataset. What are some good ways to compare the individual predictions of the two models for $N$ classes? If any ...
0answers
27 views
+100

### Reconciling wildly different $\chi^2$ independence test results (bootstrap clustering)

I have some data that should be randomly assigned to treatment $T$, and am running some tests on observables to give evidence that this is indeed the case. Let's focus on an outcome I'll call $X$, ...
2answers
121 views
+100

### Why do some regression estimates differ by a change of sign, but others don't, when I change reference level?

Suppose I have a continuous outcome y and two factorial predictors, each with two levels: ...
0answers
32 views
+150

### What is posterior predictive check, and how I can do that in R?

I am using Bayesian hierarchical modeling to predict an ordered categorical variable from a metric variable. For example, I want to regress Happiness (in 1-5 ratings) on Money (a metric variable): ...
0answers
67 views
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### State of art streaming learning

I have been working with large data sets lately and found a lot of papers of streaming methods. To name a few: Follow-the-Regularized-Leader and Mirror Descent: Equivalence Theorems and L1 ...
3answers
164 views
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### What is this bias-variance tradeoff for regression coefficients and how to derive it?

In this paper, (Bayesian Inference for Variance Components Using Only Error Contrasts, Harville, 1974), the author claims ...
1answer
28 views
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### Training set and residuals in stochastic gradient boosting

According to the Wikipedia page, the bag.fraction parameter in SGB controls the size of the random subsample of the training set on which each successive weak ...