An experimental group is the group in an experiment that receives the variable being tested. One variable is tested at a time. The experimental group is compared to a control group, which does not receive the test variable. In this way, experimental groups are used to find answers in an experiment.
1 At around 9 months of age, babies begin to pull themselves up to a standing position. 2  By 10 months of age, a baby should be able to grasp objects with thumb and forefinger.
Your baby can now see colors in different hues and has improved depth perception, which will be evident as she gazes at the colorful mobile circling over the crib. Just don't expect your child to appreciate a pastel-colored toy before about 4 to 6 months.