To support the creation of videos like this, and get exclusive content, early access, and a behind-the-scenes look at my channel, support me on patreon:

  / edmundsj  

This is part of my series on statistically designed experiments, you can find the full playlist here:    • Main Effects Explained  

In this video I discuss experimental coding, where we convert variables which have units (such as temperature in degrees, or volume in liters) to codes, typically +1, -1, and 0. I discuss why we would want to do this, and give an example where you might draw exactly the wrong conclusions if you didn't properly code the experiment.