For shows that operate pretty much continuously, we're calling the wait "shorter" if you will get into the next showing, regardless of whether that happens in one or 20 minutes. If you have to wait for the second showing, make it "average" or "longer," based on the length of the shows.
For shows that run only at fixed times during the day, select "shorter," "average" or "longer" based on the time you need to arrive early (to get enough seats for your group) being shorter, longer or the same as the average wait time in the park for other attractions that day.
Here's my first draft, subject to change according to your comments below:
Hollywood Boulevard
Great Movie Ride - Average
Echo Lake
The American Idol Experience - Shorter
Sounds Dangerous - Shorter
Indiana Jones Epic Stunt Spectacular - Average
Star Tours - Average
Streets of America
MuppetVision 3D - Shorter
Lights, Motors, Action - Average
Studio Backlot Tour - Average
Pixar Place
Toy Story Midway Mania - Longer
Mickey Avenue
Walt Disney: One Man's Dream - Shorter
Animation Courtyard
Voyage of the Little Mermaid - Shorter
The Magic of Disney Animation - Shorter
Disney Junior - Live on Stage - Shorter
Sunset Boulevard
Beauty and the Beast - Live on Stage - Shorter
Rock n' Roller Coaster Starring Aerosmith - Longer
The Twilight Zone Tower of Terror - Longer
Fantasmic! - Average Longer
"Average" can be pretty broad, too. There doesn't have to be just one, median-wait attraction as average.
This is due to the amount of shows at the park.
At the other parks either they are balanced between shows and rides (DAK and EPCOT) or ride heavy MK. DHS has 6 rides and the rest are shows. So at Tower of Terror we are affected most by both Beauty and the Beast and Lights Motor Action!.
So while each show is going on the lines for the Tower are much shorter then average then when the shows "dump" or get over with we get a higher then average lines. So during the summer you can go to the Tower and have a walk-on wait then go back an hour later and get hit with a 30-45min wait.
Now every ride is affected here and our wait time boards cant keep up!
Now at the other Parks because they arent show heavy you can easily predict what the wait time is because you dont have the ebb and flow of the shows going in and out.