what 's missing is what we call the ` wow ' factor . 
(ROOT (S (SBAR (WHNP (WP what)) (S (VP (VBZ 's) (VP (VBG missing))))) (VP (VBZ is) (SBAR (WHNP (WP what)) (S (NP (PRP we)) (VP (VBP call) (S (NP (DT the) (`` `) (NN wow) ('' ') (NN factor))))))) (. .)))
(ROOT (S (SBAR (WHNP (WP )) (S (VP (VBZ ) (VP (VBG ))))) (VP (VBZ ) (SBAR (WHNP (WP )) (S (NP (PRP )) (VP (VBP ) (S (NP (DT ) (`` ) (NN ) ('' ) (NN ))))))) (. )))