The minimal set of electroweak precision parameters

We present a simple method for analyzing the impact of precision electroweak data above and below the Z peak on flavor-conserving, heavy new physics. We find that experiments have probed about ten combinations of new-physics effects, which to a good approximation can be condensed into the effective oblique parameters S, T, U, V, X, W, Y (we prove positivity constraints W,Y >= 0) and three combinations of quark couplings (including a distinct parameter for the bottom). We apply our method to generic extra Z(') vectors.