Near-Optimal Discrete Optimization for Experimental Design: A Regret Minimization Approach

The experimental design problem concerns the selection of k points from a potentially large design pool of p-dimensional vectors, so as to maximize the statistical efficiency regressed on the selected k design points. Statistical efficiency is measured by optimality criteria, including A(verage), D(eterminant), T(race), E(igen), V(ariance) and G-optimality. Except for the T-optimality, exact optimization is NP-hard. We propose a polynomial-time regret minimization framework to achieve a (1+varepsilon) approximation with only O(p/varepsilon2) design points, for all the optimality criteria above. In contrast, to the best of our knowledge, before our work, no polynomial-time algorithm achieves (1+varepsilon) approximations for D/E/G-optimality, and the best poly-time algorithm achieving (1+varepsilon)-approximation for A/V-optimality requires k = Omega(p2/varepsilon) design points.