Detailed Record



Overcoming the pitfalls of categorizing continuous variables in ecology, evolution and behaviour


Abstract Many variables in biological research—from body size to life-history timing to environmental characteristics—are measured continuously (e.g. body mass in kilograms) but analysed as categories (e.g. large versus small), which can lower statistical power and change interpretation. We conducted a mini-review of 72 recent publications in six popular ecology, evolution and behaviour journals to quantify the prevalence of categorization. We then summarized commonly categorized metrics and simulated a dataset to demonstrate the drawbacks of categorization using common variables and realistic examples. We show that categorizing continuous variables is common (31% of publications reviewed). We also underscore that predictor variables can and should be collected and analysed continuously. Finally, we provide recommendations on how to keep variables continuous throughout the entire scientific process. Together, these pieces comprise an actionable guide to increasing statistical power and facilitating large synthesis studies by simply leaving continuous variables alone. Overcoming the pitfalls of categorizing continuous variables will allow ecologists, ethologists and evolutionary biologists to continue making trustworthy conclusions about natural processes, along with predictions about their responses to climate change and other environmental contexts.
Authors Roxanne S. Beltran ORCID , Corey E. Tarwater University of WyomingORCID
Journal Info Royal Society | Proceedings of the Royal Society B Biological Sciences , vol: 291 , iss: 2032
Publication Date 10/2/2024
ISSN 0962-8452
TypeKeyword Image review
Open Access hybrid Hybrid Access
DOI https://doi.org/10.1098/rspb.2024.1640
KeywordsKeyword Image Trustworthiness (Score: 0.47005165) , Continuous variable (Score: 0.4312506)