Title Local and global comparison of continuous functions (In Proceedings) IEEE Conference on Visualization Herbert Edelsbrunner, John Harer, Vijay Natarajan, Valerio Pascucci Visualization, Riemannian manifolds, smooth functions, time-varying data, comparison measure, differential forms. 2004 Austin, TX 275--280 We introduce local and global comparison measures for a collection of $k \leq d$ real-valued smooth functions on a common $d$-dimensional Riemannian manifold. For $k = d = 2$ we relate the measures to the set of critical points of one function restricted to the level sets of the other. The definition of the measures extends to piecewise linear functions for which they are easy to compute. The computation of the measures forms the centerpiece of a software tool which we use to study scientific datasets.