Telephone survey-based research results in higher estimates of local site visitors than does panel-based research, according to a study released Monday by the Online Publishers Association. For the
study, the OPA compared differences in methodology and features of five researchers--comScore Media Metrix, Nielsen//NetRatings MegaView Local, Nielsen//NetRatings@Plan, Scarborough Research, and The
Media Audit. Michael Zimbalist, OPA president, said the study was meant to be a snapshot of the current state of research. "Online has been relatively small, but is poised to take off," Zimbalist
said. "An accelerator in the adoption of online local advertising will be the development of more robust measurement at the local level."