Instead, Nielsen said it will adopt a "portfolio" strategy. This means focusing on improving the accuracy of its TV ratings, including additional markets for Local People Meters, measuring time-shifted viewing of digital video recorders and other video-on-demand devices and services, and expanding its national sample to include college students living outside the home, as well as other usage outside the home. Additionally Nielsen will focus on TV usage that occurs with the Internet, and with mobile media. -- Wayne Friedman