Nearest-Neighbor Classifiers requires three things
- The set of stored records
- Distance Metric to compute distance between records
- The value of k, the number of nearest neighbors to retrieve
To classify an unknown record:
- Compute distance to other training records
- Identify k nearest neighbors
- Use class labels of nearest neighbors to determine the class label of unknown record (e.g., by taking majority vote)

Definition of Nearest Neighbor

K-nearest neighbors of a record x are data points that have the k smallest distance to x
1-nearest-neighbor

Nearest Neighbor Classification
Compute distance between two points:
- Euclidean distance

- Manhatten distance

- q norm distance
