A recent ruling in FCA US v. Cummins has caused a stir in the e-discovery community. The ruling resolved a dispute between two parties, one who wanted to use keywords to cull collected data before employing a TAR process and the other who wanted to apply TAR to all collected data without any preliminary keyword culling. The court ruled in favor of the latter.

Given that keyword culling is quite commonly used to reduce the volume of data submitted for downstream review—manual or technology-assisted—it is not surprising that this ruling drew the attention of courts and practitioners alike. But, in our view, there is no universal rule governing the appropriateness or reasonableness of keyword culling.

The validity of keyword culling depends on the circumstances of the matter at hand and on the methodology adopted for developing, applying and testing the keywords. To come to a sound assessment of whether keyword culling is appropriate in a given instance, it is essential to ask questions about the situational factors surrounding the case and the specific keyword proposal being considered.