Balanced incomplete block design: A design in which all the treatments are not used in all blocks.
Such designs have the below stated properties:
* each block comprises the same number of units;
* each treatment happens the same number of times in all blocks;
* each pair of treatment combinations happens together in the block the same number of
times as any other pair of the treatments.
In medicine such type of design may be employed to ignore asking subjects to attend for treatment an unrealistic number of times, and hence possibly preventing problems with the missing values. For instance, in a study with ?ve treatments, it might be thought that the subjects could realistically only be asked to create three visits. A likely balanced incomplete design in this particular case would be the following: