# Blog Archives

## 2015.2: Did the New England Patriots experience a decrease in fumbles starting in 2007?

February 1, 2015
By

Here's a timely guest entry from Jeffrey Witmer (Oberlin College). As the “Deflate Gate” saga was unfolding, Warren Sharp analyzed “touches per fumble” for NFL teams before and after 2006, when a rule was changed so that teams playing on the r...

## Example 2014.13: Statistics doesn’t have to be so hard! Resampling in R and SAS

November 17, 2014
By

A recent post pointed us to a great talk that elegantly described how inferences from a trial could be analyzed with a purely resampling-based approach. The talk uses data from a paper that considered the association between beer consumption and mosqu...

## The Statistical Sleuth (second edition) in R

August 15, 2012
By

For those of you who teach, or are interested in seeing an illustrated series of analyses, there is a new compendium of files to help describe how to fit models for the extended case studies in the Second Edition of the Statistical Sleuth: A Course in...

## Example 9.38: dynamite plots, revisited

July 16, 2012
By

Dynamite plots are a somewhat pejorative term for a graphical display where the height of a bar indicates the mean, and the vertical line on top of it represents the standard deviation (or standard error). These displays are commonly found in many scie...

## Example 9.37: (Mis)behavior of binomial confidence intervals

July 9, 2012
By

While traditional statistics courses teach students to calculate intervals and test for binomial proportions using a normal or t approximation, this method does not always work well. Agresti and Coull ("Approximate is better than "exact' for interval ...

## Example 9.30: addressing multiple comparisons

May 7, 2012
By

We've been more sensitive to accounting for multiple comparisons recently, in part due to work that Nick and colleagues published on the topic. In this entry, we consider results from a randomized trial (Kypri et al., 2009) to reduce problem drinking ...

## Example 9.29: the perils of for loops

April 30, 2012
By

A recent exchange on the R-sig-teaching list featured a discussion of how best to teach new students R. The initial post included an exercise to write a function, that given a n, will draw n rows of a triangle made up of "*", noting that for a beginne...

## Example 9.28: creating datasets from tables

April 23, 2012
By

RThere are often times when it is useful to create an individual level dataset from aggregated data (such as a table). While this can be done using the expand.table() function within the epitools package, it is also straightforward to do directly with...

## Example 9.22: shading plots and inequalities

March 1, 2012
By

A colleague teaching college algebra wrote in the R-sig-teaching list asking for assistance in plotting the solutions to the inequality x^2 - 3 > 0. This type of display is handy in providing a graphical solution to accompany an analytic one. RThe plot...

## managing projects using RStudio

February 10, 2012
By

We're continually amazed with new developments within RStudio, the integrated developed environment for R that we highlighted previously (Among others, Andrew Gelman agrees with us about its value). The most recent addition addresses one of our earlie...