Question

Describe what is “blocking” and “randomization” and explain when and why it is a good idea to use those methods in designing experiments.

Answer 1

(a)

Blocking in experimental design is the arrangement of experimental units in groups that are similar to one another. It is a good idea to use the method of blicking,because by blocking we can eliminate the contribution to experimental error contributed by nuisance factors.

For example, to test the effectiveness of a new medicine, the participants can be spilt into2 blocks: males and females. Here blocking ised to eliminate the contribution of the nuisance factor: Gender.

(b)

Randomization in experimental design is the assigment of participants into various treament groups in a purely random manner. It is a good idea to use the method of randomization because by random assignent of participants we can eliminate any possible biases that may arise in the experiment, thus ensuring each participant have the same probability of getting into ny treatment group.