Unless you catch them in the act, even scolding them for it minutes after it happened will do no good as you will confuse them (they will think they are getting in trouble for coming to you or something). Confusing is never a good thing! Instead ignore all house accidents (unless you catch them in the act) and when they go outside, watch them (better yet, keep them on a leash), and when they go outside GO NUTS with praise!!!

Dogs CRAVE attention, positive and negative attention, so they will repeat the actions that get them the most attention. So by ignoring their actions in side the house and going nuts when they go outside, which do you think they will be more likely to repeat?

If you catch them in the act, say "NO", then correct the behavior (as in, bring them outside, then when/if they go outside, give LOTS of praise!).

Good luck!!