Section 3.7.17 Standard of Care Violations Must Be Proved by Expert Testimony

• Library: Construction Law Practice Manual 3rd Edition 2016

§ 3.7.17 Standard of Care Violations Must Be Proved by Expert Testimony

Ordinarily, in professional malpractice actions, expert testimony is necessary to prove the nature and extent of the standard of care.¹⁵⁷ In most cases, Arizona courts also require expert testimony to prove that a design professional breached that standard of care.¹⁵⁸ The role of an expert witness in a design professional case is to explain matters that are not within the common understanding of lay persons; it is not to tell the jurors how to rule or allocate responsibility among the parties to the action.¹⁵⁹ The trial court has the discretion to determine whether a witness possesses the necessary qualifications to opine on a particular subject as an expert and whether that expertise is applicable to the subject matter of the case.¹⁶⁰

Arizona has a general standard for the qualification of experts, subject to the role of trial court as gatekeeper for the admission of evidence.¹⁶¹ An expert is defined as one “who is so qualified, either by actual experience or by careful study, as to enable him to form a definite opinion of his own respecting any division of science, branch of art, or department of trade about which persons having no particular training or special study are incapable of forming accurate opinions or of deducing correct conclusions.”¹⁶² While, Arizona...