The Collaborative International Dictionary of English v.0.48:

Qualitative \Qual"i*ta*tive\, a. [Cf. LL. gualitativus, F.
   qualitatif.]
   Relating to quality; having the character of quality. --
   Qual"i*ta*tive*ly, adv.
   [1913 Webster]

   Qualitative analysis (Chem.), analysis which merely
      determines the constituents of a substance without any
      regard to the quantity of each ingredient; -- contrasted
      with quantitative analysis.
      [1913 Webster]

WordNet (r) 3.0 (2006):

qualitatively
    adv 1: in a qualitative manner; "this discoloration
           qualitatively suggests that the substance is low in
           inorganic iron"