Nonparametric Data Reduction Techniques

Definition

A nonparametric data reduction technique is a data reduction technique that does not assume any model for the data.

Key Points

Nonparametric data reduction (NDR) techniques is opposite to parametric data reduction (PDR) techniques. A PDR technique must assume a certain model for the data. Parameters of the model are determined before the data reduction is performed. A NDR technique does not assume any model and is applied to the data directly. The data reduction effectiveness of a PDR technique heavily depends on whether the model suits the data well. If well-suited, good accuracy as well as substantial data reduction can be achieved; otherwise, both cannot be achieved at the same time. A NDR technique yields more uniform effectiveness irrespective of the data, but it may not achieve as high data reduction as a well-suited PDR technique.

Popular NDR techniques include histograms, clustering and indexes. Histograms are used to approximate data distributions. An equidepth...