Which of the following is correct meaning of 'Blocking' in Randomized block design?

Correct option is A

Blocking in randomized block design involves grouping participants (or experimental units) with similar characteristics together into blocks to control for variability and reduce experimental error.

Information Booster:
• Blocking is a technique to reduce the impact of nuisance variables by creating homogeneous groups
• Each block contains participants similar on confounding variables (age, gender, ability level, etc.), and treatments are randomly assigned within each block
• Randomized block design (RBD) increases statistical power by accounting for known sources of variation
• Common examples include matched-pairs designs where participants are paired based on similarity before random assignment
• Blocking reduces within-group variance, making it easier to detect treatment effects
• This design is particularly useful when experimental units are naturally heterogeneous but can be grouped by identifiable characteristics