Someone with more expertise can probably explain this better than me (aeh?), but I think you CAN score a "scaled score" 19 and not get any raw score points beyond it (a child can earn just enough points to get the scaled score of 19, but did not earn "additional" raw score points that would give them, say, a 21). Can you see the raw score? If you can, you can check the extended norms for WISC to see what the scaled score should be if extended norms are used. HTH!