The idea behind extinction (or full extinction to differentiate it from graduated extinction) is that you want to extinguish the behaviour (crying) by not responding to it. As with the check-and-console method, go through your bedtime routine, put them in their crib awake, say good night and walk out. This is certainly the most controversial sleep-training method, and even experts disagree on what you should do next—it all depends on what stage your baby is at developmentally, as well as what works for the parents.
"I have a 3-month-old who I rock at night. He falls asleep very quickly (much quicker than if I leave him in his crib). If he wakes in the middle of the night, we go to him and comfort him. We don't take him out – we just help soothe him. Why make him feel lonely and abandoned? I have no problem losing a little sleep if it means that he feels like we will be there for him."
"I have a 6-month-old who has refused to sleep longer than 30 to 90 minutes day or night since he was born! I've tried everything out there except CIO. He's strictly breastfed and relies on that or rocking to get to sleep. He doesn't know how to soothe himself to sleep, and he naps for only 15 minutes. I'm severely sleep deprived. I don't have the heart for CIO, but I think I'll try the revised method where you pat him down and reassure him lovingly while allowing him the opportunity to comfort himself. He's been co-sleeping since day one, and it's going to be tough, but I'm at my wits' end and cannot function."
There’s also no need to institute a regimented cry-it-out plan if what you’re currently doing is working for your family. But good sleep habits never hurt, and being able to fall asleep on one’s own is a necessary life skill. If you sleep-train at a time that’s developmentally appropriate for your baby and with the basic ingredients of healthy sleep in place, you can minimize the amount of crying your baby (and, let’s face it, you) will do.