"Block design" refers to the practice of creating a research study or experiment that involves dividing subjects into groups, with each group receiving a different treatment. There are several synonyms that can be used to describe block design, including "group design," "quasi-experimental design," and "matched-pairs design." These terms all indicate that the subjects involved in the study or experiment are being grouped together in some way, and that each group is receiving a different treatment or intervention. This type of design is often used in research studies to help control variables and ensure that the results are as accurate and valid as possible.