On Becoming Baby Wise: Giving Your Infant the Gift of Nighttime Sleep (On Becoming... Book 1) by Garry Ezzo (highly recommend to all parents of newborns). The series continues on up through the teen years and is a wonderful resource in dealing with the day to day process of parenting from a Biblical perspective. As part of a baby's day, they recommend alone play time. It begins in the playpen, and as the child grows and develops it moves into their room or a designated play area in your home. However, let me just clarify, alone playtime is not to be used for extended periods of time, and as a parent you are always watching and listening.
Alone playtime is designed to teach your child that they can play without Mommy's constant stimulation, and it gives Mom a chance to do some things that are necessary for her home to function or just a time for her to sit quietly for a bit.
When Addie was about a year, I would sit her in her room on the floor with some toys around her and then stand by her door. The first several times it was for five minutes. Then gradually it increased to 10 minutes and so on. Basically, as she grew, so did her alone playtime.
Now that we have two children, alone playtime is essential. When siblings are around each other constantly, having some time to play alone is important. I have found that when alone playtime is over, they are bother excited to get back together.
Alone playtime is sometimes needed because of a child's personality. Our daughter Addie is a very social person. She would rather be with others constantly. Her personality needs alone playtime to teach her that it is possible for her to have fun alone without anyone else around. Our son Ian loves being with his sister, but his personality desires some alone time without the stimulation of others.
The hardest thing about alone playtime is the guilt that moms sometimes feel when they allow their child that time without them. I know. I have felt that guilt as well. Yet, what a gift we are giving our child! We are teaching them the art of finding ways to entertain themselves and giving their imaginations room to soar.
Alone playtime takes some time to teach and learn, but once the idea becomes an established routine in your home, you will treasure that time for the benefits your whole family will enjoy.