Attacking Class Experts' Methodology, Conclusions and Reports to Obtain or Defeat Certification

Recording of a 90-minute CLE webinar with Q&A

This program is included with the Strafford CLE Pass. Click for more information.
This program is included with the Strafford All-Access Pass. Click for more information.

Conducted on Tuesday, February 16, 2016

Recorded event now available

or call 1-800-926-7926
Course Materials

This CLE course will discuss the effective use of cross-examination to challenge an opposing expert’s methodology, conclusions and draft reports in class action litigation. The panel will outline practical strategies counsel should use during deposition and at trial to expose flaws in the expert’s opinion and ultimately prevail in demonstrating that the Rule 23(a) requirements for class certification have or have not been met.


Since Wal-Mart v. Dukes, many lower courts now require a rigorous expert analysis at the class certification stage to demonstrate that damages can be measured on a classwide basis. Expert witnesses generally opine on whether all class members have suffered injury, whether aggregate damages can be estimated with statistical accuracy, and other similar issues.

Effective cross-examination of the opposing party’s expert witnesses can influence whether a putative class action meets the Rule 23 prerequisites for certification. The goal of cross-examination is to expose flaws in the expert’s methodology, conclusions and draft reports in order to convince the judge to grant or deny certification.

Preparation is crucial when it comes to cross-examination. During expert deposition, counsel should focus on boxing in the expert regarding the opinions he or she plans to give during the certification hearing. Deposition testimony, expert reports, books or articles authored by the expert, and prior testimony in other cases are all sources of information that can be used to discredit or impeach an expert during cross-exam. Counsel must consider how to best leverage the information gained from these sources.

Listen as our authoritative panel discusses effective strategies for cross-examining experts in class action litigation. The panel will share techniques from their own experiences that have proven successful in discrediting expert witnesses in order to obtain or defeat class certification.



  1. Role of experts in class action litigation
  2. Expert witness cross-examination strategies
    1. At deposition
    2. At trial


The panel will review these and other key issues:

  • What is the role of experts in the class certification decision?
  • What cross-examination strategies should class action counsel employ during expert depositions to better position his or her case for success?
  • What cross-examination tactics have been effective for class action attorneys during the class certification hearing to discredit opposing expert witnesses?


Costello, Sean
Sean P. Costello, Esq.

Law Office of Sean P. Costello

Mr. Costello has litigated product liability cases, represented individuals in SEC and other government...  |  Read More

Keith Dubanevich
Keith Dubanevich

Stoll Berne

Mr. Dubanevich is a trial lawyer with over 30 years of experience in more than a dozen different jurisdictions around...  |  Read More

Access Anytime, Anywhere

Strafford will process CLE credit for one person on each recording. All formats include course handouts.

To find out which recorded format will provide the best CLE option, select your state:

CLE On-Demand Video