¶ 114. (concurring). I agree with the majority's decision today and write separately only to remark upon the harmless error test utilized by the majority. See majority op. at ¶ 96. The majority's standard is whether there is "a reasonable possibility that the error contributed to the outcome," and that a "reasonable possibility" is one "sufficient to 'undermine confidence in the outcome.'" Id. (quoting State v. Dyess, 124 Wis. 2d 525, 544-45, 370 N.W.2d 222 (1985)). Since the standard for harmless error is the same for civil, as well as criminal, cases (Town of Geneva v. Tills, 129 Wis. 2d 167, 184-85, 384 N.W.2d 701 (1986)), it is imperative that the standard be accurately conveyed.
*845¶ 115. For at least the past 35 years, this court has wrestled with formulating a standard for harmless error. See, e.g., Pulaski v. State, 24 Wis. 2d 450, 456-57, 129 N.W.2d 204 (1964); State v. Spring, 48 Wis. 2d 333, 339-40, 179 N.W.2d 841 (1970); Wold v. State, 57 Wis. 2d 344, 356-57, 204 N.W.2d 482 (1973); State v. Grant, 139 Wis. 2d 45, 406 N.W.2d 744 (1987). In an attempt to formulate a single, uniform test for harmless error, Dyess "conclude[d] that the test of prejudice as formulated in Strickland subsumes the various statements of the harmless error test that this court has used over the years." Dyess, 124 Wis. 2d at 545.1 The Strickland case referred to is Strickland v. Washington, 466 U.S. 668, 693 (1984), and the test is whether "there is a reasonable probability" that "but for" the error, "the result of the proceeding would have been different. A reasonable probability is a probability sufficient to undermine confidence in the outcome." 466 U.S. at 694 (emphasis added). Dyess obviously adopted that test, but incorrectly assumed that there was no real difference between using "reasonable possibility" instead of "reasonable probability." 124 Wis. 2d at 544. Granted, Dyess applied its test by stating that "[i]n the present case, the probability to be weighed is whether the defendant would have been acquitted." Id. at 546 *846(emphasis added). However, as evident in the majority's opinion here today,2 Wisconsin courts have frequently used the term "reasonable possibility," and have not indicated that, in the context of a harmless error standard, possibility means probability.3
¶ 116. There can be no doubt that there is a significant difference between what is reasonably probable and what is reasonably possible. "A possibility test is the next thing to automatic reversal." Wold v. State, 57 Wis. 2d 344, 356-57, 204 N.W.2d 482 (1973).4 While I agree that the focus should be "on whether the error 'undermine[s] confidence in the outcome,'" (Dyess, 124 Wis. 2d at 545 (quoting Strickland, 466 U.S. at 694)), if that error need only possibly under*847mine the confidence in the outcome, rather than probably, appellate courts, and circuit courts considering motions after verdict and post-convictions motions, will find themselves invading the purview of the jury. A cornerstone of the common law is deference to the jury, which is diluted by determining whether the alleged error possibly, and only possibly, may have affected the jury's decision.
¶ 117. I do not take issue with the term "reasonable possibility," so long as it is made clear that this term means reasonable probability, and probability is the standard to be applied. Accordingly, I offer the following test for harmless error, which makes clear that Dyess' use of the term "reasonable possibility" is intended to require "reasonable probability":
Wisconsin Stat. § 805.18(2) provides that an error requires reversal only where it has "affected the substantial rights of the party" claiming error. We have long recognized that the focus of a court's analysis under this statute is whether, in light of the applicable burden of proof, the error is significant enough to "undermine confidence in the outcome" of the trial. Dyess, 124 Wis. 2d at 544-45. An error is significant enough to undermine confidence in the outcome if there is a reasonable probability of a different outcome without the error. Dyess made it clear that "probability" is substantially the same as "possibility" under Wisconsin law. Id. at 544.
¶ 118. Even though the majority used a "reasonable possibility" test, the alleged error at issue here — the admission of Paul Cacioli’s expert opinion regarding the safety of Smith & Nephew's gloves — would be harmless under the more stringent "reasonable probability" test. As the majority points out, the jury heard evidence similar to that offered by *848Cacioli from other sources. See majority op. at ¶ 98. Also, the jury heard that Cacioli did not consider himself an expert on the issue of how protein levels affect those who use the gloves. See id. at ¶ 99. Given Caci-oli's proviso, the jury could have accepted or disregarded his opinion. However, there was other similar evidence that the jury could have relied upon. Consequently, there is no reasonable probability that the admission of Cacioli's opinion, assuming arguendo, it was error to do so, affected the jury's verdict.
¶ 119. That Wisconsin courts have often used "reasonable possibility" rather than "reasonable probability" should not dissuade the court from correcting such missteps today. See, e.g., State v. Sullivan 216 Wis. 2d 768, 792, 576 N.W.2d 30 (1998); State v. Alexander, 214 Wis. 2d 628, 653, 571 N.W.2d 662 (1997). There is no time like the present — dum fervet opus5 — when the court has before it five cases wherein it discusses the harmless error standard, to clarify Dyess.
¶ 120. For the reasons stated herein, I respectfully concur.
¶ 121. I am authorized to state that Justice JON P. WILCOX joins this opinion.
Dyess single test for harmless error standard has not been without controversy. State v. Dyess, 124 Wis. 2d 525, 370 N.W.2d 222 (1985). In addition to the majority opinion's discussion of Dyess' harmless error standard, authored by Justice Day, in State v. Grant, 139 Wis. 2d 45, 406 N.W.2d 744 (1987), Chief Justice Heffeman, Justice Day, Justice Abrahamson, and Justice Callow separately concurred on the Dyess issue. The controversy has continued. See State v. Dodson, 219 Wis. 2d 65, 92-98, 580 N.W.2d 181 (1998) (Crooks, J., concurring, joined by Justice Steinmetz and Justice Wilcox).
See also Koffman v. Leichtfuss, 2001 WI 111, 246 Wis. 2d 31, 630 N.W.2d 201; Martindale v. Ripp, 2001 WI 113, 246 Wis. 2d 67, 629 N.W.2d 698; Evelyn C.R. v. Tykila S., 2001 WI 110, 246 Wis. 2d 1, 628 N.W.2d 768; and Nommensen v. American Cont'l Ins. Co., 2001 WI 112, 246 Wis. 2d 132, 629 N.W.2d 301. (I have written dissents or concurrences in these cases.) But see State v. Lindell, 2001 WI 108, 245 Wis. 2d 689, 629 N.W.2d 223 (Strickland's probability sufficient to undermine the confidence in the outcome test used to determine ineffective assistance of counsel claim).
According to my research, on few occasions since Dyess has this court, in a majority opinion, noted that reasonable possibility means reasonable probability. See State v. Armstrong, 223 Wis. 2d 331, 372 n.40, 588 N.W.2d 606 (1999); see also State v. Huntington, 216 Wis. 2d 671, 695-96, 575 N.W.2d 268 (1998). However, several court of appeals opinions have applied the Dyess harmless error test using the correct "reasonable probability" standard. See, e.g., State v. A.H., 211 Wis. 2d 561, 569, 566 N.W.2d 858 (Ct. App. 1997); State v. Joseph P., 200 Wis. 2d 227, 237, 546 N.W.2d 494 (Ct. App. 1996).
Woid's "reasonable probability" test for harmless error was replaced by Dyess' "reasonable possibility" test.
"While the action is fresh; in the heat of action." Black's Law Dictionary 518 (7th ed. 1999).