TV programs viewed online are more engaging than those screened on a television set. That is the main finding of Simmons Research’s "Multi-Media Engagement" study, as cited in MediaPost.

In order to measure engagement, Simmons had consumers rate media on trustworthiness, inspirational value, and other attributes.

Viewers were 47% more engaged in ads shown during TV programs
shown online than those shown on programs watched on a TV set. They
were also 25% more engaged in the content of shows watched online than
on a set.

The online effect was true for magazines as well. Consumers
were 18% more engaged with ads in online versions of magazines compared
with print versions, and 15% more engaged in magazine articles online
than in print magazines.

In general, however, print had higher levels of engagement than TV or the Internet.

The survey was conducted online and by telephone from October 2006 to September 2007.

Via eMarketer