Sometimes you’ll find a pattern that you think is accurate, but then it will fail to accurately predict one of your tests. That is actually a good thing. You’ve learned something new and now you have the chance to revise your pattern and make it even better. For example, consider the new scenario below. Follow each of the steps one at a time and predict what you think will happen. If you do not have a real syringe available, you may use the syringe simulator instead to see what happens.
Hmm… not very exciting. The plunger stayed at 20. But the plunger started at 35 before we pushed down on it, so when we released the plunger, shouldn’t it have gone back up to 35? Why didn’t our über-pattern work in this scenario?
Our über-pattern works only when the blue cap is on the syringe, or when the syringes are connected in a way that prevents anything from getting in our out of them. When nothing can get in or out of the syringes, we are going to say that the syringe system is “closed.” And when things can get in or out of the syringes, we are going to say that the syringe system is “open.” We just have to modify our über-pattern to say that it only works when the syringe system is closed.