You spent hundreds or thousands on a fancy new HDTV -- so you ought to be able to tell when you're watching a high-definition television program vs. one of those moldy old standard-def shows, right?

Alas, that's not quite the case. A full 18 percent of HDTV owners can't tell the difference between SD and HD, according to a survey from Leichtman Research Group, which polled over 1,300 U.S. households about what they were watching.

The confusion largely seems to lie with the issue that many HDTV buyers don't understand that their existing cable TV feeds come at standard-definition resolution and that a service upgrade has to be purchased in order to get high-def programming. To this day numerous consumers just don't get it that a high-def cable signal isn't included with the TV set itself, and that additional hardware is required in order to decode an HD signal. It also doesn't help matters that many cable and satellite providers offer low-grade transmissions that stretch the definition of HD, so compressed that you can't really be blamed for not being able to tell the difference vs. SD, even if you are watching the higher-end service.

This all bodes poorly for the rest of the high-def video world. If consumers can't tell the difference between a crummy, roughly VHS-quality broadcast and high-definition, what hope do they have when comparing, say, DVD vs. Blu-ray, which are closer in quality level?

Do you have HDTV programming for your HDTV? Are you sure?