Controlling the Outcome Even more sophisticated systems would let viewers control the outcome of a drama.

One problem the networks face is letting viewers know about the new content during commercials, Mr. Close said.

"Tuesdays With Morrie" lets viewers off just as easily, but its cathartic ending is emotionally genuine.

Letting viewers reshuffle the TV schedule cripples the network's ability to build audiences for new shows by putting them on after hits.

They also worry that letting viewers watch shows like "Friends" at any time might sap the lucrative demand for reruns in syndication.

"Fata Morgana" let viewers decide for themselves how successfully the dancers had fought the black magic that ensnared them.

The impetus for the remote control was as much to silence advertisements as to let viewers remain on the couch.

Pasdar's uncompromising performance, one of the best things about "Profit," doesn't let viewers off the hook.

Entertainment Television, Ms. Summerford gazed at the camera and let viewers in on the secret.

A bit soppy, but bittersweet enough to let viewers make an important transition gracefully.