Glossary
Plain definitions, no fluff.
- Drowsy But Awake
- The state most sleep training methods ask you to put your baby down in: sleepy and ready for sleep, but with eyes still open, rather than already asleep. It's the starting point that lets a baby practice actually falling asleep in the crib, which is the skill most methods are built to teach. How to choose a method →
- Extinction Burst
- A temporary increase in crying or protest, sometimes seen on the second night of an extinction-based method, before things improve. It reflects a baby testing whether the previous response pattern still applies, not the method backfiring, and typically settles if the plan is held consistently. Graduated extinction, in depth →
- Room-Sharing
- Baby's sleep space (a crib, bassinet, or play yard) in the same room as the parent, but not in the same bed. The AAP recommends room-sharing without bed-sharing for at least the first 6 months, stating it can reduce SIDS risk by as much as 50 percent. Safe sleep basics →
- Safe Sleep ABC
- Alone, Back, Crib: the AAP's shorthand for safe infant sleep. Baby sleeps alone (not in an adult bed or with a drowsy caregiver), on their back, in a crib or equivalent firm, flat surface with nothing else in it. These basics apply for every sleep, at every age covered on this site, regardless of sleep training method. Full safe-sleep explanation →
- Sleep Consolidation
- The gradual process of a baby's sleep organizing into longer, more continuous stretches instead of frequent short wakings. It happens naturally with development, and is also what most sleep training methods aim to speed up by teaching a baby to resettle independently between normal, brief sleep-cycle transitions. The 4-month sleep regression →
- Sleep Latency
- How long it takes to fall asleep after being put down. It's one of the two outcomes most often measured in sleep training research, alongside the number and length of overnight wakings, and the one that improved fastest for both graduated extinction and bedtime fading in the randomized trial cited on this site. See the full comparison →
- Sleep Pressure
- The biological drive to sleep that builds the longer a baby has been awake. Bedtime fading works directly with sleep pressure: it moves bedtime to match the point where sleep pressure is already high enough for a baby to fall asleep quickly with minimal fuss, then shifts that time earlier in small steps. Bedtime fading, in depth →
- Split Night
- A pattern where a baby sleeps well for the first stretch of the night but then wakes for an extended period in the early morning hours (often 3 to 5am) and struggles to resettle. It's a common sticking point during sleep training and is usually addressed by adjusting the bedtime or wake window rather than by changing the method itself.
- Wake Window
- The stretch of time a baby is awake between sleep periods. Wake windows lengthen predictably as babies get older, and putting a baby down for a nap or bedtime too early or too late relative to their current wake window is one of the most common reasons a sleep plan struggles, independent of which method you're using.