Wilson ⑤ developed the Edited Nearest Neighbor (ENN) algorithm in which S startsout the same as TS, and then each instance in S is removed if it does not agree with themajority of its k nearest neighbors (with k=3, typically). This edits out noisy instancesas well as close border cases, leaving smoother decision boundaries. It also retainsall internal points, which keeps it from reducing the storage requirements as much asmost other reduction algorithms. Algorithmically, the ENN scheme can be expressed asfollows: