Polynomial regression with covariates in SPSS: Identifying and describing a quadratic relationship @mikecrowson2462

Uploaded May 2022 | Updated September 2026, 2 weeks ago

In this video, I walk you through an approach for identifying and describing a quadratic functional relationship between a focal independent variable and the dependent variable in a linear regression that includes covariates. I discuss identification of non-linearity using residuals plots and an approach for graphing a quadratic functional relationship between the IV and DV while holding the covariates constant at their means.
The example is based around a discussion in Chapter 12 of Darlington & Hayes (2017) book: afhayes.com/regression-analysis-and-linear-models.html

Download a copy of the data used in the video here: drive.google.com/file/d/11LIpryp2MbGMG0C8aszUnjPM43sLcbdH

Supplemental powerpoint: drive.google.com/file/d/1cDTTe7VfuzZVwMt4tq5IIb__djBquF26

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