310 search results for "ANOVA"

A weird and unintended consequence of Barr et al’s Keep It Maximal paper

January 2, 2015
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Barr et al's well-intentioned paper is starting to lead to some seriously weird behavior in psycholinguistics! As a reviewer, I'm seeing submissions where people take the following approach:1. Try to fit a "maximal" linear mixed model.  If you get...

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Interpreting regression coefficient in R

November 23, 2014
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Interpreting regression coefficient in R

Linear models are a very simple statistical techniques and is often (if not always) a useful start for more complex analysis. It is however not so straightforward to understand what the regression coefficient means even in the most simple case when there are no interactions in the model. If we are not only fishing for

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A look at the igraph package

November 13, 2014
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A look at the igraph package

by Joseph Rickert The igraph package has become a fundamental tool for the study of graphs and their properties, the manipulation and visualization of graphs and the statistical analysis of networks. To get an idea of just how firmly igraph has become embedded into the R package ecosystem consider that currently igraph lists 72 reverse depends, 59 reverse imports...

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Let’s Do Some MORE Hierarchical Bayes Choice Modeling in R!

November 3, 2014
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Let’s Do Some MORE Hierarchical Bayes Choice Modeling in R!

R enables us to "test drive" statistical models by running simulations and analyzing actual data. We can look at the output and get some sense of how the whole thing works. The goal is to provide a realistic application that is not too difficult to fol...

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Analysing a randomised complete block design with vegan

November 3, 2014
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Analysing a randomised complete block design with vegan

It has been a long time coming. Vegan now has in-built, native ability to use restricted permutation designs when testing effects in constrained ordinations and in range of other methods. This new-found functionality comes courtesy of Jari (mainly) and my efforts to have vegan permutation routines use the permute package. Jari also cooked up a standard interface...

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Type III tests and R

October 28, 2014
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by Terry M. Therneau Ph.D. Faculty, Mayo Clinic About a year ago there was a query about how to do "type 3" tests for a Cox model on the R help list, which someone wanted because SAS does it. The SAS addition looked suspicious to me, but as the author of the survival package I thought I should understand...

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New Course! A hands-on introduction to statistics with R by A. Conway (Princeton University)

October 13, 2014
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New Course! A hands-on introduction to statistics with R by A. Conway (Princeton University)

The best way to learn is at your own pace. Combining the interactive R learning environment of DataCamp and the expertise of Prof. Conway of Princeton, we offer you an extensive online course on introductory statistics with R.  Start learning now… Whether you are a professional using statistics in your job, an academic wanting a

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Get Some Class

October 13, 2014
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Get Some Class

By Chris Campbell – Senior Consultant, UK. R is a classy language. Look: x <- matrix(1:9, nrow = 3) x ## ## 1 4 7 ## 2 5 8 ## 3 6 9 class(x) ## … Continue reading →

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Newcastle R course, a write-up

September 22, 2014
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I recently attended a week-long R course in Newcastle, taught by Colin Gillespie. It went from “An Introduction to R” to “Advanced Graphics” via a day each on modelling, efficiency and programming. Suffice to say it was an intense 5 days! Overall it was the best R course I’ve been on so far. I’d recommend it to others,...

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An exercise in non-linear modeling

September 7, 2014
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An exercise in non-linear modeling

In my previous post I wrote about the importance of age and why it is a good idea to try avoiding modeling it as a linear variable. In this post I will go through multiple options for (1) modeling non-linear effects in a linear regression setting, (2) benchmark the methods on a real dataset, and (3) look at how...

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