Non-Parametric Regression vs Parametric Regression

An Introduction

Suraj Ghimire
Apr 22, 2020 · 3 min read
Image for post
Image for post
Photo by M. B. M. on Unsplash
  1. The outputs are called the responses, or classically the dependent variables.
  2. A function that maps or explains the relation between input and output. in supervised learning, they are well known as regression functions. They correspond to the case where the outputs are quantitative.
Image for post
Image for post
An example of a statistical model. Figure by author
  1. If we do not have any model, we use a non-Parametric approach
Image for post
Image for post
An example of a parametric approach: fig by author
Image for post
Image for post
a non-parametric approach

Why the non-parametric model?

  1. It allows great flexibility in the possible form of the regression curve and makes no assumption about a parametric form.
  2. It only assumes that the regression curve belongs to them some infinite-dimensional collection of functions.
  3. It heavily relies on the experimenter to supply only qualitative information about the function and let the data speak for itself concerning the actual form of a regression curve.
  4. It is best suited for inference in a situation where there is very little or no prior information about the regression curve.


The parametric form of regression is used based on historical data; non-parametric can be used at any stage as it doesn’t take any presumption. However, parametric and non-parametric regression is not a contradiction of each other. While the subsequent computation of non-parametric form, based on the first result can be used as a parametric form, any type of parametric regression can be used as non-parametric to test the accuracy of the model that we are using for parametric regression.

Data Science Everyday

Diving to everyday data

Medium is an open platform where 170 million readers come to find insightful and dynamic thinking. Here, expert and undiscovered voices alike dive into the heart of any topic and bring new ideas to the surface. Learn more

Follow the writers, publications, and topics that matter to you, and you’ll see them on your homepage and in your inbox. Explore

If you have a story to tell, knowledge to share, or a perspective to offer — welcome home. It’s easy and free to post your thinking on any topic. Write on Medium

Get the Medium app

A button that says 'Download on the App Store', and if clicked it will lead you to the iOS App store
A button that says 'Get it on, Google Play', and if clicked it will lead you to the Google Play store