Eventually his sleep cycle will become more established and, when he experiences the
partialPartial (focal) seizure
Partial thromboplastin time (ptt)
Thyroid gland removal waking episodes that every person experiences, he will not wake fully as he is doing now. When young children wake up at night they are often scared, and this results in their seeking out their parents. You are doing the
correctCorrect (new formula) thing by taking him back to his own bed. You can read about sleep stages on the following (and many others) we site:
http://www.med.umich.edu/1libr/yourchild/sleep.htm
Also, you can see a much more detailed description in Richard Ferber's book: Solve Your Child's Sleep Problems