Aug 18, 2013 — Correlation — Correlation is a measure of the extent to which two variables change together.  A positive correlation means that when we increase one variable, the other increases as well.  It also means that when we decrease one variable, the other decreases... Read more

Aug 18, 2013 — R (squared) Statistic — I remember making plots in middle and high school, and this curious r-squared statistic told me something about how well my data fit some regression plot.  I had no clue where this value came from, but I noticed that it... Read more

Aug 15, 2013 — What is Standard Error? — Let’s say that I have a huge file cabinet filled with pasta (choose your favorite kind from “the Plethora of Pasta Permutations”) and I want to know the volume of each piece (let’s say there is a contest to guess... Read more

Aug 15, 2013 — Visual: How Sampling can Approximate a True Relationship — We know from central limit theorem and the law of large numbers that when we take a bunch of random samples from some unknown distribution, and then look at the distribution of sample means, as our number of samples goes... Read more