Rewarding softness
	• If a datapoint is exactly halfway between two clusters, each cluster should obviously have the same responsibility for it. • The responsibilities of all the clusters for one datapoint should add to 1. • A sensible softness function is the entropy of the responsibilities. – Maximizing the entropy is like saying: be as uncertain as you can about which cluster has responsibility – We want high entropy responsibilities, but we also want to focus the responsibility for a data-point on the nearest cluster centers.
									Responsibility of cluster i for datapoint j
				Number of clusters, k
					Entropy of the responsibilities for datapoint j