Guesstimating Seat Time

Many eLearning projects are priced out based on expected "seat time" -- that is, how long the learner has to sit on his or her butt to learn (watch!) what needs to be presented/taught.

I've never been that good at estimating seat time and often end up with projects that are longer than they're supposed to be. This is not good from either the learner's point of view or the development team's.

I have a lot of issues with the whole "seat time" model (and I'm thinking about sit and click style eLearning here of the self-paced variety):

• My seat time may be different than yours
• Is there supplemental material, like reading, that is optional -- or that might vary per user?
• How interactive is the course going to be?
• Is the user being forced to watch every single page or do they have freedom to jump around.
  
• ETC.
• ETC.
  

What would you add to this list?

There's some metrics floating around: such as 4 hours of classroom time = 1 hour of eLearning time. But that varies wildly if you're talking software training vs. something more complex and soft.

How do you estimate seat time?

Or, better yet, what's the alternative to seat time as the basis for a pricing model?

Photo credit: Shock and sorrow: chair mass grave by emdot