Lack of training in the area in-which he/she should have learned; causing deficient learning knowledge
The learning knowledge that a child/person should have learned with in a time period can cause a learning deficient.
(Example) Learning is to gain knowledge, understanding, or skill.(This is in accordance with the great Webster.) An even broader definition of learning is "any permanent change in behavior that occurs as a result of a practice or an experience." This makes what we teach our children even more important as it has the potential to have a lasting affect in their behavior. Alphabetarian sounds and (reading), Problem solving skills (math), research (science)(geography)