What is the purpose of blocking in some experiments?

Question

Madeline Alexander · Accepted Answer

If the variability is not known to be uniform, then we may use blocking to attain homogeneity within the blocks

In Design of Experiments it is assumed that the population variance is fixed at say,#sigma# , throughout the field of experimentation. It also lead to randomised Block designs from Simple random designs, this increases efficiency of the test procedure.

Elena Atkins · Answer

undefined The purpose of blocking in some experiments is to reduce or eliminate the variability caused by extraneous factors or sources of variation that are not of primary interest to the researcher. Blocking involves grouping experimental units based on a known or suspected source of variation and then randomly assigning treatments within each block. This ensures that any differences observed between treatments are more likely to be due to the treatment itself rather than the blocking factor.

Blocking is particularly useful when there are known sources of variability that could affect the response variable, but which are not the main focus of the experiment. By blocking, researchers can account for these sources of variability and improve the precision and accuracy of their estimates of treatment effects. Blocking also helps to increase the efficiency of an experiment by reducing the overall variability in the data, which can lead to more reliable conclusions.

Overall, the purpose of blocking in experiments is to control sources of variation that are not of primary interest, thereby improving the validity and reliability of the experimental results.