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Election 2008: Struggle Between Tradition and Innovation
Today is Monday, November 3rd. Election Day, when the U.S. picks its 44th President, is less than 24 hours away. And as of Saturday night, just 72 hours before the polls close, […]
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Why I
My valentine is unique. It will not provide me with flowers, or chocolates, or a romantic dinner tonight, and will certainly not whisper sweet nothings into my good ear. And yet – […]
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Pareto Charts in R
A Pareto Chart is a sorted bar chart that displays the frequency (or count) of occurrences that fall in different categories, from greatest frequency on the left to least frequency on the […]
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Bar Charts and Segmented Bar Charts in R
Here are a couple of tutorials I’ve written to help anyone who’s interested in learning how to produce simple bar charts or simple segmented bar charts in R, given that you have […]
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Normal Probability Plots (QQ Plots) in R
Here’s a tutorial on how to tell whether your data are (approximately) normally distributed! qq-plot-75-925
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Text Analysis Tutorial on Spam Email in R
Hi everyone – I just wrote a tutorial on text analysis in R using the tm and wordcloud packages. Thought some of you here might be interested in it: text-analysis-75-925
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Performance Measures for Classifiers: Precision, Recall, and F1
Here is a new, simple tutorial on how to evaluate the quality of a classifier. The attached doc shows you how to construct a confusion matrix, compute the precision, recall, and f1 scores […]
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Type I Error, Type II Error, and Power Analysis in R
At some point in the life of most quality engineers, quality managers, and Six Sigma Black Belts and practitioners — you will have to compute an appropriate sample size to ensure that the results […]
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Typing x-bar, y-bar, p-hat, q-hat, and all that! In Microsoft Word
I use Microsoft Word to prepare documents. I do not like Microsoft Equation Editor. And I have to type equations and expressions not often (like every sentence or every other sentence), but […]
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Contingency Tables with gmodels in R
Contingency tables provide a way to display the frequencies and relative frequencies of observations, which are classified according to two categorical variables. The elements of one category are...
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A Linear Congruential Generator (LCG) in R
In my simulation classes, we talk about how to generate random numbers. One of the techniques we talk about is the Linear Congruential Generator (LCG). Starting with a seed, the LCG produces the first...
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Why the Ban on P-Values? And What Now?
Just recently, the editors of the academic journal Basic and Applied Social Psychology have decided to ban p-values: that’s right, the nexus for inferential decision making… gone! This has created...
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One-proportion z test in R
For quite a while, I’ve been confused by the behavior of the prop.test function in R: 1) the p-values always seem to be slightly off, and 2) the confidence intervals never seem to be symmetric around...
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Sampling Distributions and Central Limit Theorem in R
The Central Limit Theorem (CLT), and the concept of the sampling distribution, are critical for understanding why statistical inference works. There are at least a handful of problems that require you...
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Randomly Sample Twitter Followers in R
Image Credit: Doug Buckley at http://hyperactive.to So yesterday, I set up an #AmazonGiveaway for my new R book at https://giveaway.amazon.com/p/ea32d421d8d7672d — but I had my 10 year old input the...
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What (Really) is a Data Scientist?
Drew Conway’s very popular Data Science Venn Diagram. From http://drewconway.com/zia/2013/3/26/the-data-science-venn-diagram What is a data scientist? What makes for a good (or great!) data scientist?...
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A Simple Intro to Bayesian Change Point Analysis
The purpose of this post is to demonstrate change point analysis by stepping through an example of the technique in R presented in Rizzo’s excellent, comprehensive, and very mathy book, Statistical...
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A 15-Week Intro Statistics Course Featuring R
Morgan at Burning Man 2014. (Image Credit: Nicole Radziwill) Do you teach introductory statistics or data science? Need some help planning your fall class? I apply the 10 Principles of Burning Man in...
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Logistic Growth, S Curves, Bifurcations, and Lyapunov Exponents in R
If you’ve ever wondered how logistic population growth (the Verhulst model), S curves, the logistic map, bifurcation diagrams, sensitive dependence on initial conditions, “orbits”, deterministic chaos,...
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My First (R) Shiny App: An Annotated Tutorial
Image Credit: Doug Buckley of http://hyperactive.to I’ve been meaning to learn Shiny for 2 years now… and thanks to a fortuitous email from @ImADataGuy this morning and a burst of wild coding energy...
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