http://www.bailii.org/ew/cases/EWHC/Ch/2016/256.html

"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. The judge in this case advised that "best practice" would be for a single, senior lawyer, who has mastered the issues in the case, to 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.

In this case, the parties had agreed the use of predictive coding, but had sought approval for this from the court. Other than a fleeting reference to predictive coding in one earlier case, there has been no other consideration of this issue by the English courts to date. However, other jurisdictions (such as the US and Ireland) have endorsed the use of this software.

Master Matthews has now given his approval to the parties to use predictive coding. He noted that nothing in the rules/practice directions prohibits its use and there is no evidence that it leads to less accurate disclosure (indeed, it can be more accurate and consistent). In this particular case, a full manual review of over 3 million documents would be unreasonable. Predictive coding would also cost far less than the full manual alternative. Since the "value" of the claims made in this case runs to tens of millions of pounds, the estimated costs of using the software were proportionate.  It was also of relevance that the trial would not take place for over a year, and so there would be plenty of time to consider other disclosure methods, if that becomes necessary. The Master further noted that the parties had agreed the use of the software.

The Master did caution, though, that: "Whether it would be right for approval to be given in other cases, will, of course, depend upon the particular circumstances obtaining in them".