The Collaborative International Dictionary of English v.0.48:

conceptualization \conceptualization\ n.
   the act of formulating or making a concept of something.

   Syn: conceptualisation, formulation, formularizing,
        formularising.
        [WordNet 1.5]

   2. an elaborated concept.

   Syn: conceptuality.
        [WordNet 1.5]

WordNet (r) 3.0 (2006):

conceptualization
    n 1: inventing or contriving an idea or explanation and
         formulating it mentally [syn: conceptualization,
         conceptualisation, formulation]
    2: an elaborated concept [syn: conceptualization,
       conceptualisation, conceptuality]