Biplots are two-dimensional plots that help to visualize relationships in high dimensional data. A previous article discusses how to interpret biplots for continuous variables. The biplot projects observations and variables onto the span of the first two principal components. The observations are plotted as markers; the variables are plotted as
This is an issue I hear about from parents all of the time. Sometimes the disagreements are small, and sometimes they are very significant. As your child ages, the stakes become even higher when parents can't get on the same page. Here are a few common ways that parents find themselves
The t-test is a very useful test that compares one variable (perhaps blood pressure) between two groups. T-tests are called t-tests because the test results are all based on t-values. T-values are an example of what statisticians call test statistics. A test statistic is a standardized value that is calculated
