transaction or occurrence test legal definition

test used under federal law to determine whether a particular claim should have been filed as a counterclaim and will be barred from future filing as a separate claim. The four separate suggested tests are: 1) Are factual and legal claims raised by claim and counterclaim really the same? 2) Would a later suit be barred by res judicata if it werenÂ’t for the compulsory counterclaim rule? 3) Will essentially the same evidence support or refute both the plaintiffÂ’s claim and the counterclaim? 4) Are claim and counterclaim largely related?