( ( ( Measurement errors ) ( that ( result ( from ( failing ( to ( take ( into ( ( ( account these ) and ) ( ( other sources ) ( of variability ) ) ) ) ) ) ) ) ) ) ) ( ( will ( ( underestimate risks ) ( that ( swimmers experience ) ) ) ) . ) )
(ROOT (S (NP (NP (NNP Measurement) (NNS errors)) (SBAR (WHNP (WDT that)) (S (VP (VBP result) (PP (IN from) (S (VP (VBG failing) (S (VP (TO to) (VP (VB take) (PP (IN into) (NP (NP (NP (NN account)) (NP (DT these))) (CC and) (NP (NP (JJ other) (NNS sources)) (PP (IN of) (NP (NN variability)))))))))))))))) (VP (MD will) (VP (VB underestimate) (NP (NNS risks)) (SBAR (IN that) (S (NP (NNS swimmers)) (VP (VBP experience)))))) (. .)))
Measurement errors that result from failing to take into account these and other sources of variability  will underestimate risks that swimmers experience.
(ROOT (S (NP (PRP You)) (ADVP (NP (NP (NN decrease) (NNS errors)) (PP (IN in) (NP (DT an) (NN experiment)))) (IN by)) (VP (VBP take) (NP (JJ many) (NNS measurements))) (. .)))