Hi, I'm Janet Kennedy. I'm a licensed clinical psychologist and sleep specialist in New York City. You can find out more about me and my work on my website, nycsleepdoctor.com. Ferberizing has become the generic label for all versions of "cry-it-out" sleep training strategies. The rationale for allowing your baby to cry to learn how to sleep is this: when babies are first born, they wake up frequently throughout the night, and we respond to them with feeding and with soothing, because that's what they need. They're not able to soothe themselves throughout the night. As they get older though, they wake up just out of habit, and they might not need to feed throughout the night, and they might be capable of self-soothing, if given the chance. Cry-it-out strategies allow the baby to cry until they fall asleep so that they can learn to soothe themselves instead of expecting to get help from the parents. The Ferber method involves checking on the baby at timed intervals that increase in length over the course of the night, and over the course of several days. By checking on the baby, the parent is offering soothing words, but is not allowed to pick up the baby or soothe the baby to sleep. Other cry-it-out strategies suggest not checking at all, because seeing the parent can start a new wave of crying and might prolong it. Most cry-it-out strategies involve night weaning as well, so that the baby is not getting fed in response to crying. But if your baby is not ready to go all the way through the night without a feeding, you can incorporate one feeding at a specific time during the night, or even a second, if your doctor advises. These strategies are controversial because people have significant concerns about whether it's okay to allow a baby to cry alone in a crib. If you have concerns about this, you should talk to your doctor about whether this is an appropriate strategy for you.