All Posts

R parts of speech

Almost everyone who writes computer commands starts by copying and modifying existing commands. To do this, you need to be able to read command…

Two-sample or not two-sample

I’ve been talking to a lot of statistics instructors about their introductory courses, particularly which topics they choose to include in the course.…

Little Apps for teaching stats

Interactive apps are a powerful way to engage students with statistical concepts. Several textbooks have apps associated with them, for instance, the…

The 95% range

Statistics vocabulary is replete with intervals, ranges, errors, and estimates. Even at the introductory level, there are standard errors, margins of…

Smoothing and Covariates

The Little App on smoothing and covariates has two distinct (but related) purposes. […] A covariate is a potential explanatory variable,…

Little Apps: Center and Spread

Possibly the first statistic students encounter is the mean. In a statistics course, they soon discover its partner, the standard deviation. At the…

Jittering

In StatPREP, we make extensive use of a graphical technique called jittering. It’s likely that the word “jitter” is not in the index of your textbook.…

Model-T Statistics

Statistics and automobiles have timelines that overlap nicely: […] There’s much more history to come, of course. […] Imagine you…

Little Apps: Two-sample t test

The two-sample test app is a common fixture of intro stats, deservedly or not. It’s usually described as addressing this question: Is there a…

Little Apps: Proportions and zero/one variables

Consider this textbook exercise, written in a style that will be familiar to anyone who has taught introductory statistics.1 […] In late June…