Source : Webster's Revised Unabridged Dictionary (1913)

Shallowness \Shal"low*ness\, n.
   Quality or state of being shallow.

Source : WordNet®

shallowness
     n 1: lack of depth of knowledge or thought or feeling [syn: {superficiality}]
          [ant: {profundity}]
     2: the quality of lacking physical depth; "take into account
        the shallowness at that end of the pool before you dive"
        [ant: {deepness}]