Optimal Experimental Design: A Tutorial for the odr Package and od-main Shiny App

When designing experimental studies, researchers perform power analyses to determine the sample sizes needed to have a reasonable chance of detecting treatment effects if they exist. In the meantime, sample size allocation matters when sampling costs vary across treatment conditions and levels. While theoretical frameworks for optimal design exist, their practical application often requires specialized programming skills that can be a barrier for many applied researchers. To address this, our tutorial introduces two accessible and powerful tools: the odr R package and its companion web interface, the od-main R Shiny app.