DEALING WITH OUTLIERS AND INFLUENTIAL POINTS WHILE FITTING REGRESSION

Authors

  • Chuda Prasad Dhakal Tribhuwan University, Institute of Agriculture and Animal Sciences (IAAS), Rampur, Chitwan

DOI:

https://doi.org/10.3126/jist.v22i1.17741

Keywords:

Outliers, Influential points, Studentized residual, Leverage value, Cook's distance

Abstract

Dealing with outliers and influential points while fitting regression is recognizing them, identifying the reasons to their existence in the process and employing the best alternatives to lessen their effect to the fitted regression model. In this paper, before considering elimination of outliers and the influential points while fitting a regression, as they contain important information, issues why unusual observations (possible outliers) appear in the process and how to analyze them to detect if they were real outliers, have been discussed thoroughly. And, when detected as outliers and influential points, to investigate and eliminate their effect in the fitted model, analytic procedures; leverage value, studentized residuals and cook's distance were carefully employed to optimize a multiple regression model for rice production forecasting in Nepal. This model was fitted with 35 years (1961-1995) time series data, collected from Ministry of Agriculture and Cooperatives, Food and Agriculture Organization Statistics Database, International Rice Research Institute and Department of Hydrology and Metrology which to its end was consisted of the three predictors, price at harvest, rural population and area harvested.

Journal of Institute of Science and Technology
Volume 22, Issue 1, July 2017, Page: 61-65

Downloads

Download data is not yet available.
Abstract
1766
PDF
2240

Downloads

Published

2017-07-18

How to Cite

Dhakal, C. P. (2017). DEALING WITH OUTLIERS AND INFLUENTIAL POINTS WHILE FITTING REGRESSION. Journal of Institute of Science and Technology, 22(1), 61–65. https://doi.org/10.3126/jist.v22i1.17741

Issue

Vol. 22 No. 1 (2017)

Section

Research Articles

License

The views and interpretations in this journal are those of the author(s). They are not attributable to the Institute of Science and Technology, T.U. and do not imply the expression of any opinion concerning the legal status of any country, territory, city, area of its authorities, or concerning the delimitation of its frontiers of boundaries.

The copyright of the articles is held by the Institute of Science and Technology, T.U.