The use of technology that has the potential to greatly reduce the costs of discovery and make the process more manageable for all involved has been approved by the English High Court. TAR, or technology assisted review, was previously approved by the Irish courts in March 2015 in the IBRC/Quinn litigation.


TAR is a method for identifying relevant electronic documents in the discovery process using a combination of predictive coding software and expert human input. In simple terms, a person trains the computer software to determine whether documents are relevant to the litigation (For a more detailed explanation, see our previous article on TAR here).


Traditional discovery involves the following basic stages:

  • identification of discoverable documents (i.e. documents which potentially have to be disclosed to the other side);
  • preservation and collection of discoverable documents;
  • processing, review and analysis of discoverable documents to identify relevant documents; and
  • production of relevant documents.

Ordinarily at the processing/review/ analysis stage, junior lawyers manually review the documents to determine relevance. Once the initial stages of review are complete, senior lawyers carry out a final review. In a large scale discovery, this process can be extremely time-consuming and an enormous drain on resources. Indeed, anecdotal evidence suggests that in complex litigation the cost of discovery can sometimes amount to close to 50% of the costs incurred.


TAR can assist with the processing/ review/analysis stage. Once trained, the software ranks the documents in terms of relevance. This ensures that the most relevant documents are delivered to the senior lawyers for review first. By engaging senior lawyers at the outset, rather than at the final review stage, the volume of potentially relevant documents can be reduced at an early stage and the discovery process shortened. This has the potential to translate into significant savings in terms of time and cost.


The courts in Ireland, the US and now England have identified a number of possible benefits of using TAR as compared to traditional discovery:

  • reduction of lawyer review time;
  • reduction of costs;
  • quicker completion of the discovery process;
  • delivery of a more consistent review; and
  • more accurate discovery.


While TAR has been judicially approved, it is not suitable in all cases. To justify its use, the cost of employing TAR must be less than the estimated cost of a manual review. When considering using TAR, the following factors are important:

  • the volume of documents to be reviewed;
  • the estimated costs of review;
  • the time-frame for review; and
  • the value of the claims in a particular case.


Ireland In 2015, Mr. Justice Fullam of the Irish High Court approved the use of TAR in litigation involving IBRC and the members of the Quinn family. The judge found that, provided the process is sufficiently transparent, the use of TAR discharges a party’s discovery obligations as set out in the Irish court rules. In this case, the Quinns objected to the process proposed by IBRC. However, the judge said that where the party seeking to use TAR acts in good faith, and the proposed process is transparent, opposition should not deter a court from allowing its use.

This decision is under appeal to the Court of Appeal.


The English High Court has now also approved the use of TAR in Pyrrho Investments Ltd v MWB Property Ltd. In so doing, the Court was guided by the decision of the Irish High Court in the IBRC/Quinn case, and the decision of the Southern District of New York in Da Silva Moore v. Publicis Groupe & MSL Groupe. The Court found that the case was particularly suited to TAR as it involved a high value claim (upwards of £20 million) and a large volume of documents (upwards of 3 million). The Court also noted that:

  • other jurisdictions have found that TAR is useful in appropriate circumstances;
  • there is no evidence that TAR is less accurate than manual review and it may in fact be more accurate;
  • using TAR provides greater consistency as all the documents are reviewed for relevance on the basis of training from a single or small team of senior lawyers instead of being manually reviewed by a large team of junior lawyers;
  • there are no prohibitions on the use of TAR; and
  • the parties agreed to the use of TAR.


Both the Irish and English courts have endorsed TAR as an acceptable and useful tool in the discovery process. While the use of TAR is a matter to be determined by the court on the facts of a particular case, its ongoing judicial acceptance in common law jurisdictions is welcomed and has the potential to greatly reduce the costs of discovery and render the process more manageable for all parties, especially in large-scale discovery processes.