Most of the examples they give I have already dealt with in my "Fake Civilians" series but it is a good place to see them all at once. I am actually cited for one of their photos. (I also had a post on evidence of children being recruited for terror activities.)
An examination of about a third of the names of Palestinians killed in Operation Protective Edge revealed several instances of children and teenagers serving as military operatives in the terrorist organizations. The examination also revealed instances in which the ages of Palestinian casualties were falsified by Gaza's Hamas-controlled ministry of health. For example, boys aged 15 and 17 were integrated into the terrorist operative networks; the age of a nine year-old terrorist auxiliary was listed as 24; and a terrorist operative in his twenties was listed as 13 years of age.
Children and teenagers in Gaza's educational system undergo basic military training in the schools and summer camps.[1] Using them as auxiliaries and sometimes as operatives, in ITIC assessment, is not limited to isolated cases although at this stage it is difficult to estimate the extent of the phenomenon.
They also showed photos of children of terror commanders playing with weapons, but they had no evidence that those children were actually militants.
I'm still waiting for the center to publish the remainder of their research on the number of terrorists killed in Gaza.
(h/t Gary, Gidon S)