Category: Blog

Factor analysis, like almost all forms of data analysis, is just matrix factorization. Let be a matrix containing observations of variables (or indicators). We suppose that the variables in can be written as linear combinations of unobserved (or latent) factors, … Read more

Out of sheer boredom, I decided to try my hand at implementing the Solitaire encryption algorithm in R. Solitaire was developed by Bruce Schneier for Neil Stephenson’s Crytonomicon, and is designed to be implemented using only a deck of … Read more

The Iowa Gambling Task has always been one of my favorite tasks, if only because it’s so much fun to analyze. In the standard version of the task, subjects select a card on each trial from one of four decks … Read more

A while back, a friend of mine asked me to help out in a longitudinal project trying to predict cognitive decline in (otherwise healthy) older adults (Mulligan, Areshenkoff, & Smart, 2015). One of the measures we used was resting state … Read more

One can argue the choice of when to stop collecting data should be irrelevant to our choice of parameter estimates, since all information should be contained in the likelihood function. This principle underlies some criticisms of standard hypothesis testing, where … Read more

One major research program in our lab aims to understand how the motor system makes use of task related and perceptual information when planning and executing movement. For example, a right handed “reach and grasp” action is executed more quickly … Read more

Edit (05/11/15): The article has been retracted.

Psychological Science recently published a paper — Sadness Impairs Color Perception¹ — which has been causing a bit of a ruckus on the statistics blogosphere. Psych Science already has a bit … Read more