Sleep training means using behavioral techniques to teach your baby to sleep independently by altering her “sleep onset associations” — or the circumstances your baby needs to fall asleep at bedtime. By removing your presence at bedtime, you are providing new associations with the result that she will learn to fall asleep independently, both at bedtime and when she awakens during the night.
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.
Prepare yourself for a few difficult nights. Hearing your baby cry can be excruciating, as every parent knows. During the waiting periods, set a timer and go to a different part of the house, or turn on some music, so you don't have to hear every whimper. As one BabyCenter parent says, "The first week could be rough. Try to relax and know that when it's all over, everyone in your household is going to sleep more easily and happily."
But when he was about three-and-a-half months old, the routine fell apart. “I would feed him, but he wouldn’t be asleep at the end of the feed,” recalls Welk. “I would rock him until he fell asleep and put him down, and then he would wake up 30 minutes later and I would do it all over again.” Desperate for some rest, Welk brought Greyson into bed with her, but then she ended up just lying still, holding a pacifier in his mouth all night long. “I didn’t know anything about sleep,” says Welk. “I didn’t know you couldn’t just rock them to sleep and then put them down.”