randomized block design

A randomized block design is an experimental design where different treatments are distributed in a random order within a block or plot. This method is used in statistics to obtain data for studies by conducting experiments.12

In this design, variables of interest are identified, and some are controlled as factors to observe their influence on a response variable. For example, if studying the effect of different gasoline additives on fuel efficiency across cars from various manufacturers, a randomized block design would ensure each additive is tested on an equal number of cars from each manufacturer. This prevents differences in engine design (the block) from skewing the results for the gasoline additives (the treatments). Blocking allows for comparisons of treatments within homogeneous groups of experimental units.2