"Predictive coding" (also known as technology, or computer, assisted review), is a method whereby software analyses documents and "scores" them for relevance, and thereby reduces both the time and costs needed to complete an electronic disclosure exercise. Typically, the parties agree a protocol and a representative sample of potentially relevant documents is then obtained. A single, senior lawyer, who has mastered the issues in the case, will usually then consider the initial representative sample (marking it as relevant or not), in order to "train" the software to review the whole document set. Further statistical sampling by humans (usually taking at least 3 rounds) is then conducted to ensure the quality of the exercise. Once an acceptable level of accuracy is reached, the software then categorises all the documents.

Weekly Update 07/16 reported the decision of Pyrrho Investments Ltd v MWB Property, in which the parties had agreed the use of predictive coding, but had sought (and received) approval for this from the court. In this case, one party objected to the use of predictive coding.

Registrar Jones held that predictive coding should be ordered. He applied the various factors identified in the Pyrrho decision, and placed importance on the "extremely significant" costs saving (or around £120k, on a conservative estimate), although he noted that cost alone is not a determining factor. It must be shown that the predictive coding will be effective and achieve the disclosure required. That does not depend merely on the software used – it also requires the parties to identify what documents should be disclosed within the context of proportionality and the overriding objective. It was held that there was nothing, as yet, to suggest that predictive coding could not achieve that (in the same way that a keyword search would).

It was also held that the lawyers must "identify by reference to the true issues, the anticipated categories of documents and to enter into discussions to minimise the work required". Accordingly, directions were given for the parties to "sit down before the predictive coding begins in order to discuss the criteria to adopt and the general process of disclosure".