Randomized Block design ( RBD or RCBD):

• First experimental units are divided into blocks.
• Treatments are then assigned at random within the blocks.
• Blocks are homogenous in nature.
• There are two factors in RCBD i.e. block effects and treatment effects.
• Blocks are created to control known source of variation.

i) Complete randomized block design:

• Experimental units are divided into blocks.
• Treatment combinations are assigned randomly to the experimental units within a block.
• Every treatment occurs in each block.

ii) Incomplete randomized block design

• Not every treatment occurs in each block.

Advantages of RCBD

• More precise than CRD.
• No restrictions over number of treatments or replicates.
• If experimental errors is heterogenous, valid comparisons can still be made.
• Cheaper to run.

Disadvantages of RCBD

• Implementing the design is difficult and requires advanced knowledge of a specific discipline.
• Large variation can result in long term error
• Can’t function if there is missing data.
• Software for calculation not easily available