The variance sum law and its implications for modelling

Basic understanding of linear model is primordial in quantitative psychology and modelling. As an advanced topic for students in psychology, modelling data according to given sets of parameters can be challenging. In this paper, we address the variance sum law which states how to combine variance of...

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Bibliographic Details
Main Authors: Caron, Pier-Olivier, Lemardelet, Laura
Format: Article
Language:English
Published: Université d'Ottawa 2021-06-01
Series:Tutorials in Quantitative Methods for Psychology
Subjects:
r
Online Access:https://www.tqmp.org/RegularArticles/vol17-2/p080/p080.pdf
Description
Summary:Basic understanding of linear model is primordial in quantitative psychology and modelling. As an advanced topic for students in psychology, modelling data according to given sets of parameters can be challenging. In this paper, we address the variance sum law which states how to combine variance of variables into a new one. The paper uses a progressive pedagogical approach, presenting step by step the statistical prerequisites. An example with code in R is offered to support the presentation. Some matrix algebra is gently introduced to stimulate readers to more advanced topics. We hope this paper can stimulate research in data modelling and invite newcomers to the fields.
ISSN:1913-4126