Effectiveness is the capability of producing a desired result. When something is deemed effective, it means it has an intended or expected outcome, or produces a deep, vivid impression.
The average newborn sleeps about 16 hours a day, but some need much less sleep and some much more. Also, it's not uncommon for a newborn's sleep pattern to change from day to day; he may sleep substantially less than usual one day and then catch up by sleeping more the following day.
Finally, newborns vary greatly in the total amount of time they spend sleeping. In the first few days, the average newborn sleeps between 16-18 hours a day (Iglowstein et al 2002). By four weeks, newborn sleep averages about 14 hours. But the range is considerable. Some four-week-old babies sleep as little as 9 out of 24 hours.