Load packages library(tidyverse) Why small effects need big samples That’s a question that periodically comes up in class. Suppose someone is planning a study. As demanded by her teacher, she computes the needed sample size upfront. So the question arises: Given some to-be-achieved level of power (80%), some effect size, and some other details: How large does my sample need to be? Some students are puzzled by the fact that small effects need larges …