Contents
What are unstandardized residuals?
An unstandardized residual is the actual value of the dependent variable minus the value predicted by the model. Standardized, Studentized, and deleted residuals are also available. The difference between an observed value and the value predicted by the model.
What is the purpose of a residual plot?
A residual plot is typically used to find problems with regression. Some data sets are not good candidates for regression, including: Heteroscedastic data (points at widely varying distances from the line). Data that is non-linearly associated.
Which is an example of a Studentized residual?
In statistics, a studentized residual is the quotient resulting from the division of a residual by an estimate of its standard deviation. It is a form of a Student’s t -statistic, with the estimate of error varying between points. This is an important technique in the detection of outliers.
What is the standard deviation of the distribution of internally studentized residuals?
The standard deviation of the distribution of internally studentized residuals is always 1, but this does not imply that the standard deviation of all the ti of a particular experiment is 1. For instance, the internally studentized residuals when fitting a straight line going through (0, 0) to the points (1, 4), (2, −1), (2, −1) are
How are internally studentized residuals used to identify outliers?
The good thing about internally studentized residuals is that they quantify how large the residuals are in standard deviation units, and therefore can be easily used to identify outliers: An observation with an internally studentized residual that is larger than 3 (in absolute value) is generally deemed an outlier.
How to calculate studentized residuals in Stat 462?
Consider the following plot of n = 4 data points (3 blue and 1 red): The solid line represents the estimated regression line for all four data points, while the dashed line represents the estimated regression line for the data set containing just the three data points — with the red data point omitted.