Monthly Archives: January 2013

Elements of Statistical Learning: free book download

January 9, 2013
By

The go-to bible for this data scientist and many others is The Elements of Statistical Learning: Data Mining, Inference, and Prediction by Trevor Hastie, Robert Tibshirani, and Jerome Friedman. Each of the authors is an expert in machine learning / prediction, and in some cases invented the techniques we turn to today to make sense of big data: ensemble...

Read more »

Every NFL punt since 2002

January 9, 2013
By
Every NFL punt since 2002

The site reddit told us about data on every single NFL (U.S. National Football League) play since 2002. We read it in and did an analysis of punting. The results are beautiful. The post Every NFL punt since 2002 appeared first on Decision Science News.

Read more »

Getting Access data into R

January 9, 2013
By

Revisiting Cronbach 1951 via Simulation with Shiny

January 9, 2013
By
Revisiting Cronbach 1951 via Simulation with Shiny

At the time of the creation of this blog, Cronbach’s 1951 piece on coefficient alpha has 18,132 citations according to google scholar.  The main use of coefficient alpha is to assess internal consistency reliability of a test or survey.   Although it may have been forgotten, the proof Cronbach demonstrated established that coefficient alpha is the mean of all split...

Read more »

Revisiting Cronbach 1951 via Simulation with Shiny

January 9, 2013
By
Revisiting Cronbach 1951 via Simulation with Shiny

At the time of the creation of this blog, Cronbach’s 1951 piece on coefficient alpha has 18,132 citations according to google scholar.  The main use of coefficient alpha is to assess internal consistency reliability of a test or survey.   Although it may have been forgotten, the proof Cronbach demonstrated established that coefficient alpha is the mean of all split...

Read more »

Factor Analysis of Baseball’s Hall of Fame Voters

January 9, 2013
By
Factor Analysis of Baseball’s Hall of Fame Voters

Factor Analysis of Baseball's Hall of Fame VotersRecently, Nate Silver wrote a post which analyzed how voters who voted for and against Barry Bonds for Baseball's Hall of Fame differed. Not surprisingly, those who voted for Bonds were more likely to vote for other suspected steroids users (like Roger Clemens). This got...

Read more »

WordPress Stats in R

January 9, 2013
By
WordPress Stats in R

A trackback from Martin Hawksey’s recent post on Analysing WordPress post velocity and momentum stats with Google Sheets (Spreadsheet), which demonstrates how to pull WordPress stats into a Google Spreadsheet and generates charts and reports therein, reminded me of the WordPress stats API. So here’s a quick function for pulling WordPress reports into R. (Code

Read more »

First steps in using C++11 with Rcpp

January 9, 2013
By

The recent release of the C++11 standard has brought a lot of attention to the new language features. Rcpp, as a CRAN package, follows CRAN policy in not (yet!!) supporting the standard for its purported non-portable status. Even as of the current g++ ...

Read more »

Item Response Modeling of Customer Satisfaction: The Graded Response Model

January 8, 2013
By
Item Response Modeling of Customer Satisfaction:  The Graded Response Model

After several previous posts introducing item response theory (IRT), we are finally ready for the analysis of a customer satisfaction data set using a rating scale.  IRT can be multidimensional, and R is fortunate to have its own package, mirt, with excellent documentation (R.Philip Chalmers).  But, the presence of a strong first principal...

Read more »

Annoucing the Rcpp Gallery

January 8, 2013
By

Earlier this morning, JJ announced what we had been working on for the last few weeks: the Rcpp Gallery. Now, as our luck will have it, the Rcpp-devel list received his message but did not transmit it for an apparent mail system outage at WU Vienna:...

Read more »