What is Block Sampling?

Block sampling is a sampling technique used in auditing, where a sequential series of selections is made. This approach is very efficient, since a large cluster of documents can be pulled from one location. However, a more random selection method would do a better job of sampling the entire population. When using block sampling, sampling risk can be reduced by selecting a large number of blocks of samples.

Disadvantages of Block Sampling

The chief concern with block sampling is that it may not be representative of the underlying population, since it is taken from a small, densely clustered group.

Example of Block Sampling

An auditor elects to use block sampling to examine customer invoices, and intends to pick 50 invoices. She picks invoice numbers 1000 through 1049. As another example, the auditor decides to pick all invoices issued on April 15.