Marekj (@rubytester on Twitter) whipped up an awesome graphical explanation of the Agile Testing Quadrants, along with an animated sketch. If you’re new to the Quadrants (aka Agile Testing Matrix from Brian Marick), these will help you grok their purpose and how to use them. The slide deck contains references for further learning on the Quadrants. Many thanks to Marekj for this contribution to our agile and testing community!