In this installment of our ongoing Statistics to English Translation series1, we will look at the technical meaning of the term ”significant”. As you might expect, what it means in statistics is not exactly what it means in everyday language.
As always, a pdf version of this article is available as well. Continue reading Statistics to English Translation, Part 2a: ’Significant’ Doesn’t Always Mean ’Important’
Scientists, engineers, and statisticians share similar concerns about evaluating the accuracy of their results, but they don’t always talk about it in the same language. This can lead to misunderstandings when reading across disciplines, and the problem is exacerbated when technical work is communicated to and by the popular media.
The “Statistics to English Translation” series is a new set of articles that we will be posting from time to time, as an attempt to bridge the language gaps. Our goal is to increase statistical literacy: we hope that you will find it easier to read and understand the statistical results in research papers, even if you can’t replicate the analyses. We also hope that you will be able to read popular media accounts of statistical and scientific results more critically, and to recognize common misunderstandings when they occur.
The first installment discusses some different accuracy measures that are commonly used in various research communities, and how they are related to each other. There is also a more legible PDF version of the article here.
Continue reading “I don’t think that means what you think it means;” Statistics to English Translation, Part 1: Accuracy Measures
New PDF slides version (presented at the Bay Area R Users Meetup October 13, 2009).
We at Win-Vector LLC appear to like R a bit more than some of our, perhaps wiser, colleagues ( see: Choose your weapon: Matlab, R or something else? and R and data ). While we do like R (see: Exciting Technique #1: The “R” language ) we also understand the need to defend oneself against the abuse regularly dished out by R. Here we will quickly share a few fighting techniques.
Continue reading Survive R
What makes a good graph? When faced with a slew of numeric data, graphical visualization can be a more efficient way of getting a feel for the data than going through the rows of a spreadsheet. But do we know if we are getting an accurate or useful picture? How do we pick an effective visualization that neither obscures important details, or drowns us in confusing clutter? In 1968, William Cleveland published a text called The Elements of Graphing Data, inspired by Strunk and White’s classic writing handbook The Elements of Style . The Elements of Graphing Data puts forward Cleveland’s philosophy about how to produce good, clear graphs — not only for presenting one’s experimental results to peers, but also for the purposes of data analysis and exploration. Cleveland’s approach is based on a theory of graphical perception: how well the human perceptual system accomplishes certain tasks involved in reading a graph. For a given data analysis task, the goal is to align the information being presented with the perceptual tasks the viewer accomplishes the best. Continue reading Good Graphs: Graphical Perception and Data Visualization
REPOST (now in HTML in addition to the original PDF).
This paper demonstrates and explains some of the basic techniques used in data mining. It also serves as an example of some of the kinds of analyses and projects Win Vector LLC engages in. Continue reading A Demonstration of Data Mining
Our first “exciting technique” article is about a statistical language called “R.”
R is a language for statistical analysis available from http://cran.r-project.org/ . The things you can immediately do with it are incredible. You can import a spreadsheet and immediately spot relationships, trend and anomalies. R gives you instant access to top notch visualization methods and sophisticated statistical methods.
Continue reading Exciting Technique #1: The “R” language.