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.
Milestones of Talking. By the age of 18 months, your toddler should begin to master the use of sounds T, D,N W and H.. According to BabyCenter.com, learning to make these specific sounds opens the door to forming new words and marks a pivotal transition for your child's speaking abilities.