"As you modify your baby's sleep behavior, you are going to have to give up middle-of-the-night crutches, known as negative associations, that may get her back to sleep in the short run but won't prevent her from popping up again in an hour. She may resist the change. The behavior may even get worse before it gets better as she adjusts to new routines, to new positive associations."
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.
The most well known cry it out technique is the one developed by pediatrician Richard Ferber, director of the Center for Pediatric Sleep Disorders at Children's Hospital Boston. Ferber says that in order to fall asleep on their own and sleep through the night, babies have to learn to soothe themselves. Ferber believes that teaching a baby to soothe himself may involve leaving him alone to cry for prescribed periods of time.
This is a very gentle, no-tears/no-cry (or very little cry) method of sleep coaching where you “fade it out” (FIO). With the Fading method, you continue to help your baby fall asleep (by rocking or feeding to sleep, for instance), but over time, you gradually do less and less of the ‘work’ to put your baby to sleep, and your baby does more and more. For instance, if you normally rock your baby completely to sleep, you may shorten the amount of time you rock each night until you are rocking for only a few minutes only as a part of the bedtime routine. This method requires quite a bit of patience on the parent’s part, in some cases, but it’s great for families who want to minimize crying as much as possible.
12 baby-sleep tips for exhausted new parents Before you even think about “training” your baby to fall asleep on their own, make sure you’re following a regular schedule and putting them to bed at a consistent time each night (hint: early is usually better, typically around 7 or 8 p.m.). Starting at about two months old, it’s a good idea to try to put them down drowsy but awake whenever you can, just to get them (and you) used to it, even if they fuss a bit. Make sure that they’ve been awake for an appropriate amount of time before bed (an over- or under-tired baby will have trouble falling asleep), and establish a calming and consistent bedtime routine, like a feed, bath or massage followed by pyjamas and stories or songs. Some experts recommend feeding at the beginning of the routine to avoid having the baby associate the feeding with falling asleep. Ideally, your baby won’t have started to nod off at any point during your bedtime routine. “You really want to make sure your baby is primed for sleep,” says Pamela Mitelman, a psychologist in Montreal who specializes in infant and child sleep. Be conscious, too, of filling their daytime awake periods with enough activity and stimulation, says Garden. “Kids need to be moving in all sorts of ways when they are awake, not just sitting in a bouncy chair,” she says.