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.
By the age of four, children may be able to draw and name. pictures and to copy shapes and letters. To do these things, children must have. usable vision. Babies who have vision problems may. learn to âseeâ in a way that is different. from babies with normal vision.