Introduction:Expert Testimony

Although the landmark United States Supreme Court case of Daubert v. Merell Dow Pharmaceuticals created a set of guidelines for when and how to admit expert testimony in many cases, standards for admissibility vary from state to state. See generally Daubert, 509 U.S. 579 (1993).

In Texas, practitioners should be guided by the Texas Rules of Evidence (TRE), as well as the Daubert-Robinson rules, which are discussed herein.


Texas is unique, in that its rules concerning the admissibility of expert witness testimony expand and broaden the scope of the Daubert standard. See, e.g, Thomas C. Riney, “Expert Witness-Back to the Basics,” State Bar of Texas Annual Advanced Evidence & Discovery Course, 2012.

The admissibility doctrine in Texas, often referred to as the Daubert-Robinson Standard, is rooted partially in Daubert and partly in the Robinson case, which was decided by the Texas Supreme Court in 1995. See generally E.I. du pont de Nemours & Co, Inc. v. Robinson, 923 S.W. 2d 549 (Tex. 1995).

The Texas Rules of Evidence further codify the standard for admitting expert testimony in §§ 702-06.

According to the TRE, testimony by expert witnesses is admissible if “scientific, technical, or other specialized knowledge will assist the trier of fact to understand the evidence or to determine a fact in issue, a witness qualified as an expert by knowledge, skill, experience, training, or education may testify thereto in the form of an opinion or otherwise.” TRE, § 702.

Accordingly, there are two components to consider in determining whether or not expert evidence is admissible:

  1. The knowledge must “assist the trier of fact to understand the evidence or determine a fact in issue,” (this may be referred to as the “helpfulness” requirement).
  2. The witness must be qualified to testify as an expert. Riney, supra.

Part I: Assisting the Trier of Fact:

As one continuing legal education instructor explains,

“The mere fact that a witness has specialized knowledge, skill, expertise or training does not necessarily mean that the opinion is admissible. The evidence must assist the trier of fact.” Id.

In order to meet this requirement, the testifying expert must possess knowledge and experience that are beyond an average juror’s and will help a judge and jury to either “understand the evidence or determine a fact issue.” Id., citing K-Mart Corp. v. Honeycutt, 24 S.W. 3d 357, 360 (Tex. 2000).

If the knowledge that an expert relays is common enough for a jury to understand on its own, then such evidence fails to meet this first requirement. Id.

A number of Texas courts have deemed expert evidence inadmissible because it did not assist the jurors. See, e.g., GTE Southwest Inc. v. Bruce, 998 S.W. 2d 605, 619-20 (Tex. 1999).

In addition, if an expert witness renders a legal opinion, this testimony is inadmissible under the first component of TRE 702. Riney, supra.

The rationale for this decision by Texas is that such opinions intrude upon “the trial court’s province to determine law.” Id.

Simply put, questions of law are considered within the realm of the trial judge, while questions of fact that are not considered common knowledge are the role of expert witnesses.

However, the fact that an expert in Texas should not provide a legal opinion can be somewhat misleading on its face, as experts are often called upon to prove legal elements of a case, such as causation, injuries, and the like.

To wit, there are numerous cases in which expert testimony is not only critical but is required in order for a litigant to appropriately set forth a cause of action.

The following instances offer a few examples of cases in which expert evidence is appropriate and/or required:

  • (a) In cases involving a claim of bad faith on the part of an insurance provider, expert testimony is considered to be appropriate. See, e.g., Royal Maccabees Life Ins. Co. v. James, 146 S.W. 3d 340, 353 (Tex. App. Dallas—pet. denied).
  • (b) Where medical matters are at issue, expert testimony is required in order to establish causation that would fall outside of “the common knowledge and experience of the jurors.” Insurance Co. of North America v. Myers, 411 S.W. 2d 710, 713 (1966).
  • (c) In cases alleging legal malpractice, expert evidence is necessary to prove a causal connection between an attorney’s negligence and a client’s loss, where such a connection is not obvious to a jury or where such a connection is outside of the common knowledge of the jurors. Alexander v. Turtur & Assocs., Inc., 146 S.W. 3d 113, 119-20 (Tex. 2004).
  • (d) In personal injury lawsuits, expert testimony is required to determine whether a settlement amount is reasonable. Amerada Hess Corp. v. Wood Group Prod. Tech, 30 S.W. 3d 5, 11 (Tex. App—Houston [14th Dist.] 2000, pet. denied).
  • (e) Expert witnesses are needed in determining whether attorneys’ fees are reasonable and/or necessary. Cantu v. Moore, 90 S.W. 3d 821, 826 (Tex. App.–San Antonio 2002, pet. denied).

There are, in addition to the aforementioned instances, times when certain Texas statutes mandate the need for expert testimony and set forth particular expert qualifications for the purposes of cases arising under those particular statutes. Riney, supra.


Attorneys in Texas should familiarize themselves with the requirements in their own practice areas to determine whether and when expert witnesses will be necessary to prove a particular matter in a given lawsuit.

The first component of TRE 702 sets forth the basic idea that expert knowledge should be helpful to the trier of fact, while the case law contemplates specific situations that call for such knowledge.

Such familiarization on the part of Texas practitioners will go a long way towards successfully serving clients and achieving the best resolutions possible during litigation.

By: Kat S. Hatziavramidis, Attorney-at-Law