Nielsen said its Big Data + Panel national audience measurement technology, which relies on information about smart-TV screen viewership as well as the company’s usual panel of consumers, passed the scrutiny of the MRC, an independent organization that vets all forms of media measurement for the U.S. industry. Nielsen is the first to gain accreditation for the technology. The new data comes from audience interactions with cable and satellite set-top boxes and smart TVs across 45 million households and 75 million devices.