Note that the I/S standard deviations control for differences in firm size.
( ( Note ( that ( ( the ( I/S ( standard deviations ) ) ) ( control ( for ( differences ( in ( firm size ) ) ) ) ) ) ) ) . )
(ROOT (S (VP (NN Note) (SBAR (IN that) (S (NP (DT the) (NNP I/S) (JJ standard) (NNS deviations)) (VP (VBP control) (PP (IN for) (NP (NP (NNS differences)) (PP (IN in) (NP (NN firm) (NN size))))))))) (. .)))
Firm size does not typically vary too greatly.
( ( Firm size ) ( ( ( ( does not ) typically ) ( ( vary too ) greatly ) ) . ) )
(ROOT (S (NP (NN Firm) (NN size)) (VP (VBZ does) (RB not) (ADVP (RB typically)) (VP (VB vary) (ADVP (RB too)) (ADVP (RB greatly)))) (. .)))