Reply to the commentary "Be careful when assuming the obvious", by P.   Alday
  Here we respond to some comments by Alday concerning headedness in linguistic theory and the validity of the assumptions of a mathematical model for word order. For brevity, we focus only on two assumptions: the unit of measurement of dependency length and the monotonicity of the cost of a dependency as a function of its length. We also revise the implicit psychological bias in Alday's comments. Notwithstanding, Alday is indicating the path for linguistic research with his unusual concerns about parsimony from multiple dimensions. 
Ramon Ferrer-i-Cancho
cs.CL physics.data-an physics.soc-ph