Answer:
Testing can help them understand where they went wrong, and see if it works.
Step-by-step explanation:
How can testing actually determine which solution for a problem works best? Well let me try and answer that for you! Instead of just diving in blind, you are diving in with the ability to see the problem after-ward, and how it can cause chaos. If the solution ends up correct in the end then the test went great. But if you like said, go in blindly and just make up an solution and add it together with the others it could cause death, third-degree burns, pain, or other horrible things.
Though I might not be 100% accurate about this answer, or the explanation, I really do hope I helped you out though.