I'm going to try the short intervals to see how that goes....i'd prefer to leave him in his playpen rather than his crate when i'm gone so he'd have more room to move around but at present his crying is more hysterical when he can see me leave. How long should the intervals start out with? He cries for a good 10 to 20 minutes when i leave him and i don't want to take him out when he is still crying. Or do you start counting the time confined when the crying starts?