One out of every five people are passing up television in favor of computers in order to watch shows, according to a new report by a California research firm.

A study released this week by Integrated Media Measurement says 20% of Americans are watching episodes of their favorite primetime shows online, and that the largest portion are white, affluent, well-educated, working women aged 25-44.

‘This is the first study to show there are a significant amount of people watching primetime shows online who are not watching some portion of those shows on television,’ says Amanda Welsh, head of research for IMMI.

The study, which mirrors U.S. census data for fundamental demographics in key markets, also shows that 50% of online viewers watch the programming as it becomes available, seemingly using their computers as an alternative to TV. The other half are using the web as a means of catching episodes that they have missed, or are giving parts of episodes they have already watched another look.

Data accumulated by the study also indicates that in numerous cases, online viewing of a program is higher than DVR viewing of the same show. IMMI’s review focused on 14 primetime shows across two major American networks between the fall of 2007 and the spring of 2008.

From Media in Canada