A Student-Centered Exploration of Influential Points in Linear Regression Using Desmos

Abstract

Linear regression, an introductory statistics topic, typically involves finding and evaluating the line of best fit as well as making predictions based on it. However, the subtopic of influential points is often neglected. We present and report on findings of a series of four interactive student-centered activities in Desmos that facilitate student discovery of potential influential points and determine the conditions that would result in them having a large effect on the position and strength of a linear relationship. Placing these activities in the Desmos environment enables students to test their conjectures about leverage points and points with large residuals as they receive immediate feedback that promotes the development of understanding of influential points. Supplementary materials for this article are available online.