  We introduce a graph-parametric framework for obtaining obstruction
characterizations of graph parameters with respect to partial ordering
relations. For this, we define the notions of class obstruction, parametric
obstruction, and universal obstruction as combinatorial objects that determine
the asymptotic behavior of graph parameters. Our framework permits a unified
framework for classifying graph parameters. Under this framework, we survey
existing graph- theoretic results on most known graph parameters. Also we
provide some unifying results on their classification.
