What is blocking in experimental design

In the statistical theory of the design of experiments, blocking is the arranging of experimental units in groups (blocks) that are similar to one another. Typically, a blocking factor is a source of variability that is not of primary interest to the experimenter.

What are blocking variables?

A blocking variable is a potential nuisance variable - a source of undesired variation in the dependent variable. By explicitly including a blocking variable in an experiment, the experimenter can tease out nuisance effects and more clearly test treatment effects of interest.

Is blocking a principle of experimental design?

Blocking: Blocking means that the like experimental units should be collected together to far relatively homogeneous groups. A block is also a replicate. The main objective/ purpose of local control is to increase the efficiency of experimental design by decreasing the experimental error.

What is a block in an experiment statistics?

Definition of a Block.  A group of experimental units or subjects that are. similar in ways that are expected to affect the response to treatments.  In a block design, the random assignment of units to. treatments is carried out separately within each block.

When should blocking be used in experiment?

At a high level, blocking is used when you are designing a randomized experiment to determine how one or more treatments affect a given outcome. More specifically, blocking is used when you have one or more key variables that you need to ensure are similarly distributed within your different treatment groups.