In this paper we demonstrate how weighted majority voting with multipl
icative weight updating can be applied to obtain robust algorithms for
learning binary relations. We first present an algorithm that obtains
a nearly optimal mistake bound but at the expense of using exponentia
l computation to make each prediction. However, the time complexity of
our algorithm is significantly reduced from that of previously known
algorithms that have comparable mistake bounds. The second algorithm w
e present is a polynomial time algorithm with a non-optimal mistake bo
und. Again the mistake bound of our second algorithm is significantly
better than previous bounds proven for polynomial time algorithms. A k
ey contribution of our work is that we define a ''non-pure'' or noisy
binary relation and then by exploiting the robustness of weighted majo
rity voting with respect to noise, we show that both of our algorithms
can learn non-pure relations. These provide the first algorithms that
can learn non-pure binary relations.