  In the recent issue of PNAS, Futrell et al. claims that their study of 37
languages gives the first large scale cross-language evidence for Dependency
Length Minimization, which is an overstatement that ignores similar previous
researches. In addition,this study seems to pay no attention to factors like
the uniformity of genres,which weakens the validity of the argument that DLM is
universal. Another problem is that this study sets the baseline random language
as projective, which fails to truly uncover the difference between natural
language and random language, since projectivity is an important feature of
many natural languages. Finally, the paper contends an "apparent relationship
between head finality and dependency length" despite the lack of an explicit
statistical comparison, which renders this conclusion rather hasty and
improper.
