 We're back. It's an ABA design. An ABA design is a three-phase single-subject experimental design comprised of three parts. The A baseline condition, the B the intervention condition, and in a return to baseline, the A condition again. The criteria for exiting the first condition is stability in the behavior also known as a steady state. And again that same criteria is applied during the B condition. An example of the ABA design would be sticking with your current diet for a while and then switching to a new diet and then returning again to your old diet. A second example would be in the classroom. You could have your normal classroom rules for your baseline, then you could implement a token economy for your intervention phase, then you could remove that token economy and go back to your baseline to see if behavior was different from time from the second baseline to the first. Thank you.