Stymied by theater owners in their effort to launch a premium video-on-demand service that would make some movies available for online rental while they are still showing in theaters, Disney and Sony have begun testing such a VOD system in South Korea, the Wall Street Journal reported today (Tuesday). Executives of the four other major Hollywood studios are also keeping their eye on The Experiment, the Journal said. Studios have argued in the past that so-called Premium VOD should have little effect on ticket sales and they apparently hope that the South Korean test will validate that position. Disney and Sony movies available for rental in South Korea during the test are priced at the equivalent of about $9 -- far less than the $30 charged by DirecTV in the U.S. for a similar experimental service in 2011. That test was widely regarded as a failure.