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.
Newborns' internal clocks aren't fully developed. They sleep up to 18 hours a day, divided about equally between night and day. Newborns should be wakened every 3 to 4 hours until they have good weight gain, usually within the first few weeks.