A group of business entrepreneurs who worried about their teenage children drinking and driving decided there must be some way to approach this problem proactively. They came up with an idea for a pair of blurry goggles. They believed looking through the goggles would simulate what the world looks like when someone is seriously intoxicated. They developed a crude pair of blurry goggles to show prospective customers. This crude pair of goggles is known as a ________.