It is a well-used phrase, but science tells us that memory doesn't serve us at all well. In fact, research has shown that the memory of an honest witness giving evidence before an arbitral tribunal can easily become distorted due to the interactions that take place during the preparation and presentation of witness evidence. This is potentially of critical importance, because fact witness evidence – along with documentary evidence – is one of the key sources available to an arbitral tribunal in seeking to determine disputed issues of fact on which an entire case might turn.

Such research led the ICC Commission on Arbitration and ADR (the "Commission") to put together a Task Force to report on the accuracy of fact witness memory in International Arbitration (the "Report"). The Report, launched in January, has been hailed as ground-breaking, with the Commission claiming that it will provide guidance to arbitrators and counsel that will enhance the probative value of fact witness evidence in international arbitration.

In this blog, we have highlighted some of the steps recommended by the Report which will be of interest to clients who might find themselves in arbitration proceedings, and how the findings of the Report may impact on how arbitral tribunals deal with fact witness evidence.

Practice Direction 57AC

Interestingly, the report comes out at the same time as Practice Direction 57AC is due to be introduced into England and Wales to regulate the preparation of trial witness statements before the Business and Property Courts (see my blogfor more details). Whilst the Practice Direction and the Report grapple with similar difficulties, the Report, unlike the Practice Direction, does not provide a prescriptive code, rather it recommends a case-by-case assessment in determining which of the steps identified in the Report might be the most appropriate.


As in court proceedings, witness evidence can often take a central role in arbitration proceedings. The default approach to the presentation of witness evidence in international arbitration includes the preparation and exchange of witness statements. Witnesses and solicitors will pour a considerable amount of time and resource into the preparation of those statements, in the knowledge that those statements may have a key role in shaping the tribunal's view of the disputed facts.

However, if memory is malleable, if it can be altered, contaminated and distorted, what can be done to improve the accuracy of evidence given before the tribunal? Bearing in mind that not "one size fits all", the following are just some of the measures mentioned in the Report aimed at reducing the distorting influences often seen within the practice of witness statement preparation.

Prior to any witness interviews taking place, the Report suggests that parties consider:-

  • establishing procedures for teams to keep contemporaneous written or oral notes of issues being discussed at the time the relevant events unfold;
  • identifying and preserving witness evidence while it is still fresh and authentic – possibly by early witness interviews;
  • avoiding setting out a party line to prospective witnesses which may have the effect of modifying their recollection of events so as to match that party line; and
  • establishing how much prior discussion and contact there has been among the witnesses in order to gauge the extent to which their recollections may have already been modified.

When it comes to interviewing factual witnesses, the Report suggests that parties:-

  • meet with likely witnesses individually and avoid meeting in groups to discuss the case;
  • keep an accurate record of interviews - perhaps by keeping an audio or video recording;
  • remind the witness that it is normal to have forgotten details and events, and that if they don't remember something then they should say so;
  • distinguish between what a witness remembers and what another person may have told them or what they may have read;
  • make the questions unbiased and open ended and review them in advance to assure their neutrality;
  • avoid intervening or interruptions - let the witness tell their story first before conducting more in-depth questioning. Avoid giving feedback to the witness on their answers, positive or negative and avoid summarising the answer as this risks distorting the answer and the witness' recollection;
  • avoid needlessly showing the witness other sources of information that may contaminate their memory, such as other witness statements. Have the witnesses recount their understanding of the facts before providing them with documents that could affect their memory. If a witness is using documents to fill in a chronological narrative, their witness statement should say so.

The Report also recommends that an arbitral tribunal should be more aware of the issues surrounding witness recollection and, where appropriate be prepared to take steps in order to mitigate the effects of imperfect memories. The following measures are just some that a tribunal may consider using:-

  • discuss with parties the taking of witness evidence at the outset of the proceedings (during the case management conference);
  • provide guidance to the parties on how to moderate meetings or discussions around the giving of evidence by the witnesses;
  • require each witness statement to include information about the way in which it was prepared and the extent to which the witness has considered or discussed evidence with the other witnesses;
  • investigate at the hearing how witnesses were prepared for the hearing in order to assess the reliability of their evidence; and
  • give instructions to the witness prior to his/her examination at the hearing, including
    • to alert the witness to the importance of distinguishing between personal knowledge and information gained post event from secondary sources;
    • that "I don't know" or "I don't recall" are permissible answers to a question; and
    • to exclude witnesses from the hearing room until they have given their evidence.

Balanced Approach

The Report's authors hope that by raising awareness of the issues, tribunals and those appearing before them will be better placed to minimise the risk of memory distortion and thereby increase the probative value of witness evidence. However, the Report recognises that minimising the risk of memory distortions would involve minimising contact with post event information and that such an approach can be hugely detrimental to the efficient presentation of a case. Witnesses who testify unprepared are often unhelpful as their testimony can sometimes be vague, incoherent and fragmented. Therefore, as laudable as they are, attempts to keep witness memory "pristine" must be balanced with other practical considerations.

Those who have cases before arbitral tribunals will be relieved to know that the Report does not recommend that the preparation of witnesses and witness evidence should become subject to routine inquiry by tribunals, but only in exceptional situations, where witness preparation is an important issue going to the essence of the particular testimony.

However, the timing of the Report together with the new Practice Direction 57A in the Business and Property Courts means that awareness within the dispute resolution community of the factors known to create memory distortions, as well as some of the measures with the potential to avoid such distortion, will be greatly increased and it would not be surprising to see reference being made to these in future cases.

The impact of the Report on arbitration proceedings themselves will depend to a great extent on how much tribunals seek to intervene regarding the preparation and presentation of witness evidence. If tribunals are going to carry out an extensive investigation into how witnesses were prepared for the hearing or how many rounds of interviews were undertaken by parties, we may well see parties and counsel quickly change long established practices with regarding to the preparation of fact witness evidence.


Andrew Scott

Senior Associate