In today’s global economy, where firms in London routinely transact with partners in Laos or Los Angeles, international arbitration remains the preferred method for resolving cross-border disputes – despite economic challenges presented by shifting energy markets and trade agreements.
Retaining More Control
Arbitration offers procedural flexibility and neutrality, allowing parties to shape the process and avoid domestic court bias. Awards are widely enforceable across 172 nations under the New York Convention, reinforcing arbitration’s global utility.[1], [2]
Parties may choose their own arbitrator as long as they meet the basic qualifications of the location where the hearing will be held. The ICC International Court of Arbitration offers a public network of arbitrators that parties can access as a resource.[3] Additionally, the parties decide how many arbitrators will preside over a case.
Most commonly, there is either a sole arbitrator (agreed upon by the parties or selected by the institution) or a three-person tribunal. For the latter, each party may select one member; the third is chosen by mutual agreement or by the arbitral institution and typically serves as the presiding arbitrator. Three-person panels are preferred for complex, high-value disputes.
Filling Gaps in Knowledge
Arbitrators are often selected because they have expertise in the nature of the dispute or the substantive law involved in the contract. However, complex matters may require even more specialised knowledge beyond that of the arbitrator(s). Expert evidence is frequently necessary to help the tribunal understand complex or technical matters outside its expertise.
Generally, there are three types of expert evidence presented in international arbitral proceedings: technical, legal and financial. Technical experts provide the tribunal with information about the science and technology behind the facts in the dispute. Legal experts are needed when the laws governing the dispute are unfamiliar to the tribunal members. The financial expert can clarify issues related to delays, costs and losses caused by the problem or disruption involved.
Selecting Experts for Arbitration
Either the arbitrating parties or the tribunal can identify and appoint an expert witness. While party-appointed experts are common, tribunal-appointed experts are preferred under certain procedural rules, and each method of appointment presents specific issues.
Party-Appointed Experts
In international arbitration, expert witnesses are typically selected and engaged by the parties, similar to US courts. While parties may occasionally agree to appoint a single expert witness, concerns persist about impartiality and the ability to challenge expert opinions. When parties rely on a single expert, the award is essentially final.
Tribunal-Appointed Experts
An arbitral tribunal may choose to appoint its own expert in addition to the parties’ experts to help resolve conflicting opinions, usually when the parties’ expert reports disagree. The fees and expenses of tribunal-appointed experts are split among the parties.[4] In addition to costs, this also raises concerns that tribunal members may delegate decision-making to the expert rather than making their own impartial and reasoned judgment.
Presenting Expert Evidence
Expert evidence is typically presented through reports and/or rebuttals, as well as verbal testimony during final hearings. Experts can expect to answer questions from one or both parties’ counsel and the tribunal. When multiple experts are selected by both parties, they generally present their reports sequentially and then respond to questions from the panel and counsel in a parallel manner.
Increasingly, tribunals use “hot-tubbing,” where experts present their opinions concurrently and respond to questions in real time, helping arbitrators clarify technical evidence and resolve disagreements. This method, a supplement to traditional testimony, allows experts to ask follow-up questions and challenge or defend positions.[5] It is especially useful when multiple witnesses with varying time needs are involved, making sequential questioning confusing.[6]
Evolving Rules and Regulations
Most arbitration centres have naturally developed their own experience-based governing rules for expert witness evidence, which parties can choose to follow depending on their case issues and needs. Due to differences among laws and jurisdictions, each centre requires its own approach, which is continually refined to improve efficiency and transparency.
The Singapore International Arbitration Centre (SIAC) introduced key updates in 2025, including streamlined and coordinated procedures, preliminary decisions and mandatory disclosures of third-party funding. These updates are designed to lower costs, expedite timelines and increase transparency in complex international disputes.[7]
An ongoing global research initiative by the Chartered Institute of Arbitrators (Ciarb) aims to “maximise the effectiveness of party-appointed expert witness evidence in ADR.” The project is focused on communication dynamics, timing of expert involvement, strategies for enhancing tribunal understanding and addressing challenges during and after hearings.[8]
Emerging Trends and Challenges
As arbitration guidelines continue to evolve, so does the complexity of dispute resolution. Industries like artificial intelligence (AI), aviation, energy and finance have advanced quickly with new technology. Along with these developments, many international arbitrations now focus on technology-related issues, and each new tech “trick” boosts the need for even more specialized expertise.
A 2025 survey by international law firm White & Case, LLP, revealed a major shift in attitudes toward using AI in arbitration. AI adoption is expected to rise significantly through 2030, with many respondents planning to use AI for research and analytics and anticipating its growing role in evaluating legal arguments. The primary reasons for AI adoption were efficiency gains, cost reductions and the desire to minimise human errors. Despite overall optimism, the survey also identified ongoing concerns, such as risks of errors and bias, confidentiality issues and a lack of practitioner experience.[9]
Although survey respondents mostly supported AI use by arbitrators for administrative and procedural tasks, there was strong resistance in areas requiring discretion and judgement. The consensus is that AI will be more integrated into arbitration, but its growth must be paired with clear guidelines, transparency and training.[10] AI technology is already being used to streamline expert witness sourcing for international arbitration, but human oversight is still crucial to ensure accuracy, credibility and preparedness.
Advancing Arbitration Strategies
Through strategic partnerships and innovative technology resources, counsel can gain greater clarity and position increasingly complex arbitrations for successful outcomes. As AI tools and expert evidence guidelines continue to evolve, global industry gatherings like London International Disputes Week will remain vital for exchanging insights, building consensus and shaping the future of tech-enabled dispute resolution.
IMS Legal Strategies is honoured to sponsor LIDW and support dispute resolution lawyers across the globe. As pioneers in the expert sourcing industry, we promptly locate the precise expertise needed for your unique dispute. A dedicated engagement team provides support through each step of the case, and our experienced consultants can collaborate with your expert to design and refine presentations. Learn more and request a consultation at imslegal.co.uk.
Expert Witnesses for International Arbitration
References
[1] York Convention. “Contracting States.” New York Convention. Accessed September 11, 2025. https://www.newyorkconvention.org/contracting-states.
[2] New York Convention. “The New York Convention.” New York Convention. n.d. https://www.newyorkconvention.org/.
[3] https://iccwbo.org/dispute-resolution/dispute-resolution-services/arbitration/rules-procedure/2021-arbitration-rules/
[4] Ibid.
[5] Dezaki, Sena Gbedemah Toshi. “How Hot-Tubbing Is Shifting the Expert Evidence Paradigm.” Passle, November 16, 2020. https://angle.ankura.com/post/102hbnr/how-hot-tubbing-is-shifting-the-expert-evidence-paradigm.
[6] Jones, Doug. ”Methods for Presenting Expert Evidence.” Global Arbitration Review. September 3, 2021. https://globalarbitrationreview.com/guide/the-guide-evidence-in-international-arbitration/1st-edition/article/methods-presenting-expert-evidence#footnote-013.
[7] Nishith Desai Associates. “NEW SIAC 2025 Rules – Key Changes & Implications.” Nishith Desai Associates, January 16, 2025. Accessed September 11, 2025. https://nishithdesai.com/NewsDetails/15232
[8] Chartered Institute of Arbitrators (Ciarb). “Maximising the Effectiveness of Party-Appointed Expert Witness Evidence in ADR.” Ciarb News & Insights, July 2025. Accessed September 11, 2025. https://www.ciarb.org/news/maximising-effectiveness-expert-evidence-adr
[9] White & Case LLP. 2025 International Arbitration Survey: Arbitration and AI. June 2, 2025. Accessed September 11, 2025. https://www.whitecase.com/insight-our-thinking/2025-international-arbitration-survey-arbitration-and-ai.
[10] Ibid.