  The state-sum invariants for knots and knotted surfaces defined from quandle
cocycles are described using the Kronecker product between cycles represented
by colored knot diagrams and a cocycle of a finite quandle used to color the
diagram. Such an interpretation is applied to evaluating the invariants.
  Algebraic interpretations of quandle cocycles as deformations of extensions
are also given. The proofs rely on colored knot diagrams.
