Sensing that the days of watching television programs at appointed times on conventional TV sets may be numbered, ratings giant Nielsen Research disclosed on Wednesday that it is embarking on a plan dubbed Anytime Anywhere Media Measurement to create a comprehensive system to measure TV viewing whether it be on TV sets, personal computers, cell phones, or on mobile devices like video iPods or PlayStation portable players or in bars or dorms. Nielsen said it will begin a test this summer to measure the number of people watching TV shows on PCs via the Internet.