What happened
In a claim that directors of MWB Business Exchange had breached their duties, the company's backup tapes held more than 17.6 million files. Removing duplicates left some 3.1 million. All parties agreed to use predictive coding and asked the court to approve it. On 2 February 2016 Master Matthews of the High Court's Chancery Division gave approval, with reasons on 16 February. He found no evidence that predictive coding gives less accurate disclosure than manual review or keyword searches with manual review. He judged that the software would apply a senior lawyer's approach more consistently than many junior reviewers. He put the cost of manual review at several million pounds at least. Estimates for the software ran from £181,988 to £469,049, plus monthly hosting costs. The accuracy finding draws on US and Irish cases, and the review had not run.
Sources
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Court document, by authors with no tie to the system.
High Court of Justice, Chancery Division (Master Matthews). Pyrrho Investments Ltd & Anor v MWB Property Ltd & Ors [2016] EWHC 256 (Ch), approved judgment of 16 February 2016. Find Case Law copy, a scan of the approved judgment.
There is no evidence to show that the use of predictive coding software leads to less accurate disclosure being given than, say, manual review alone or keyword searches and manual review combined, and indeed there is some evidence (referred to in the US and Irish cases to which I referred above) to the contrary.
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Court document, by authors with no tie to the system.
High Court of Justice, Chancery Division, Companies Court (Mr Registrar Jones). Brown v BCA Trading Ltd & Ors [2016] EWHC 1464 (Ch), 17 May 2016, para. 10, quoting Pyrrho para. 33 with its cost estimates.
the estimates given in this case vary between £181,988 plus monthly hosting costs of £15,717, to £469,049 plus monthly hosting costs of£20,820
Details
AI system
- Workflow
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Removing duplicates cut more than 17.6 million restored files to some 3.1 million. All parties agreed on using the software and on how to use it. A senior lawyer reviews a sample of documents to train the software.
Follow-up
- Conditions for replication
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The number of documents is large enough to make a full manual review unreasonable. The estimated costs stay proportionate to a claim worth tens of millions of pounds. There is time before trial to use other methods if the software fails.
Entry details
- Sector
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Legal services / e-discovery.
- Purpose
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A vendor that the judgment does not name built the predictive coding software to sort documents as relevant or not, after learning from a sample that a senior lawyer reviews.
Not yet checked: model, release, provider, role, configuration, inputs and outputs, autonomy, human oversight, AI contribution, beneficiaries, reach, distribution and access, duration, every measurement question, every money question, ownership and control, dependencies, cross-border connections, geopolitical implications, replication attempts, availability, institutional decision, grounds, action and result, success criterion, every evidence question, observed or intended, alternative assessments, related entries, other identifiers, category mappings.
Cite this record
Peter H. Vartanian. (2026). English court approves predictive coding for 3 million documents (AIBD-0830). Artificial Intelligence Benefits Database, edition of 31 October 2026. https://petervartanian.xyz/aibd/records/AIBD-0830.html (archived at https://doi.org/10.7910/DVN/AADSII, version 4.0)