The bits-back argument
					data
			Gaussian 0				Gaussian 1
	• Consider a datapoint that is equidistant from two cluster centers. – The sender could code it relative to cluster 0 or relative to cluster 1. –  Either way, the sender has to send one bit to say which cluster is being used. • It seems like a waste to have to send a bit when you don’t care which cluster you use. • It must be inefficient to have two different ways of encoding the same point.