Similar to the others.

I encourage my DS2 to 'have a little rest' (if I say it's time for a sleep he will just fight me saying NO!) just on the couch and he sometimes nods off and sometimes doesn't.
I also found that they got to a certain point where if they had a nap they were later/more difficult getting to bed and it wasn't worth the 30 min to and hr I got of peace in the arvo. I think you kind of have to play it by ear and if they look/act like they need a sleep then encourage it, but if they are fine without it then just leave them. A bit of a guessing game, like a lot of parenting!

HTH