Application of a generalization of russo's formula to learning from multiple random oracles

  • Authors:
  • Jan Arpe;Elchanan Mossel

  • Affiliations:
  • Department of statistics, uc berkeley, ca 94720, usa and bertelsmann stiftung, carl-bertelsmann-strasse 256, 33311 gütersloh, germany (e-mail: jan.arpe@bertelsmann.de);Departments of statistics and computer science, uc berkeley, ca 94720, usa and department of mathematics, weizmann institute of science, rehovot 76100, israel (e-mail: mossel@stat.berkeley.edu)

  • Venue:
  • Combinatorics, Probability and Computing
  • Year:
  • 2010

Quantified Score

Hi-index 0.00

Visualization

Abstract

We study the problem of learning k-juntas given access to examples drawn from a number of different product distributions. Thus we wish to learn a function f: {−1, 1}n → {−1, 1} that depends on k (unknown) coordinates. While the best-known algorithms for the general problem of learning a k-junta require running times of nk poly(n, 2k), we show that, given access to k different product distributions with biases separated by γ 0, the functions may be learned in time poly(n, 2k, γ−k). More generally, given access to t ≤ k different product distributions, the functions may be learned in time nk/tpoly(n, 2k, γ−k). Our techniques involve novel results in Fourier analysis, relating Fourier expansions with respect to different biases, and a generalization of Russo's formula.