¶ 28. (concurring). I agree with the majority that Johnson was not denied effective assistance of counsel in this case. He has failed to establish prejudice sufficient to undermine confidence in the outcome. Strickland v. Washington, 466 U.S. 668, 694 (1984).
¶ 29. I write separately, however, because I fear that the majority has opened the door to a line of questioning which invades the province of the jury, is of no probative value, and may prove misleading. In the *647end, the majority has fashioned a test embraced by no other jurisdiction. It exchanges a bright line rule for one that may prove difficult to apply. Accordingly, I respectfully concur.
¶ 30. This case involves a defendant being asked by a prosecutor whether one of the State's witnesses was Tying" when she gave testimony incriminating the defendant. Eschewing the bright line rule of State v. Kuehl, 199 Wis. 2d 143, 150, 545 N.W.2d 840 (Ct. App. 1995), the majority concludes that the purpose and effect of the prosecutor's cross-examination of Johnson was to impeach him, not to bolster the credibility of another witness. Majority op., ¶ 2. It thus deems the cross-examination permissible. Id.
¶ 31. In the criminal context, "were they lying" questions are generally questions posed by the prosecutor to a criminal defendant during cross-examination. State v. Pilot, 595 N.W.2d 511, 516, n. 1, (Minn. 1999). Typically, the prosecutor will first ask if the defendant heard the testimony of one or more of the state's witnesses on direct examination. Id. Then, the prosecutor will ask if the witnesses' testimony was accurate. Id. If the defendant states that the witnesses' testimony was not accurate, the prosecutor will ask the defendant whether the witnesses were lying. Id.
¶ 32. Of the states that have addressed the issue, a vast majority consider such questioning improper. See, e.g., State v. Singh, 793 A.2d 226, 239 (Conn. 2002); Knowles v. State, 632 So. 2d 62, 65 (Fla. 1993); People v. Riley, 379 N.E.2d 746, 753 (Ill. App. 1978); State v. Graves, 668 N.W.2d 860, 873 (Iowa 2003); State v. Manning, 19 P.3d 84, 100 (Kan. 2001); Commonwealth v. Martinez, 726 N.E.2d 913, 923-24 (Mass. 2000); Daniel v. State, 78 P.3d 890, 904 (Nev. 2003); State v. Flanagan, 801 P.2d 675, 679 (N.M. App. 1990); Burgess *648v. State, 495 S.E.2d 445, 447 (S.C. 1998); State v. Emmett, 839 P.2d 781, 787 (Utah 1992); State v. Casteneda-Perez, 810 P.2d 74, 79 (Wash. Ct. App. 1991); Beaugureau v. State, 56 P.3d 626, 636 (Wyo. 2002).1
¶ 33. Similarly, a number of federal circuits have condemned this cross-examination tactic. See, e.g., United States v. Sanchez, 176 F.3d 1214, 1220 (9th Cir. 1999); United States v. Boyd, 54 F.3d 868, 871 (D.C. Cir. 1995); United States v. Akitoye, 923 F.2d 221, 224 (1st Cir. 1991); United States v. Richter, 826 F.2d 206, 208 (2d Cir. 1987).
¶ 34. Several reasons underlie the disapproval of such questioning. First, the function of weighing the credibility of witnesses is exclusively in the province of the jury. The Wisconsin Criminal Jury Instructions recognize this, stating:
It is the duty of the jury to scrutinize and to weigh the testimony of witnesses and to determine the effect of the evidence as a whole. You are the sole judges of the credibility, that is, the believability, of the witnesses and of the weight to be given to their testimony.
Wis. JI — Criminal 300.
¶ 35. Likewise, Wisconsin courts and commentators echo this well-established truth:
The starting point is the venerable principle that the jury is the sole judge of the credibility of witnesses. Although the jury is sometimes characterized as the "lie-detector" in the courtroom, more often it functions *649to determine the subtle shadings which distinguish inaccurate from accurate testimony. In order to preserve the jury's role, the courts have consistently held that a witness may not testify that another mentally and physically competent witness is telling the truth.
7 Daniel D. Blinka, Wisconsin Practice: Wisconsin Evidence § 608.3, at 402 (2d ed. 2001) (citing State v. Romero, 147 Wis. 2d 264, 278, 432 N.W.2d 899 (1988); State v. Haseltine, 120 Wis. 2d 92, 96, 352 N.W.2d 673 (Ct. App. 1984); Schleiss v. State, 71 Wis. 2d 733, 745, 239 N.W.2d 68 (1976)) (emphasis added).
¶ 36. Second, this type of confrontational examination has no probative value because it does nothing to assist the jury in assessing witness credibility in its fact-finding mission. Pilot, 595 N.W.2d at 518. The defendant's opinion on another witness's credibility is irrelevant. Moreover, such tactics generally are not intended to seek information at all, but instead to score rhetorical points with the jury. As one court noted, "the predominate, if not sole, purpose of such questioning is simply to make the defendant look bad" since "the accused's answer is unimportant."2 Graves, 668 N.W.2d at 872.
¶ 37. Third, such questioning may mislead the jury into believing that either the defendant or the witness bed. This, in turn, creates the risk that, in order to acquit the defendant, the jury must find that the witness has lied. Singh, 793 A.2d at 237. See also Emmett, 839 P.2d at 787 ("The prejudicial effect of such a question lies [partly] in the fact that... it puts the *650defendant in the untenable position of commenting on the character and motivation of another witness who may appear sympathetic to the jury.").
¶ 38. The fact is that inconsistencies between the testimony of two or more witnesses do not prove that one of the witnesses has committed perjury. Rather, differences of perception and memory can result in conflicting testimony without giving rise to an implication of deliberate, willful falsehood.3 The Graves court explained this, noting:
People have different perceptions of the same conversation that affect how and what they remember. Perhaps there was a misunderstanding of what was said; perhaps one person was distracted and did not fully or correctly hear the words uttered by the other person. People sometimes hear what they want to hear. It is unjust to make the defendant give an opinion as to who is lying when, in fact, it is possible that neither witness has deliberately misrepresented the truth.
668 N.W.2d at 872.
¶ 39. Despite these concerns, the majority maintains that such a tactic is permissible cross-examination. Majority op., ¶ 21. It dismisses the contrary precedent as unpersuasive. Id., ¶ 21, n. 5. Additionally, the majority insists that its conclusion "is consistent with the results reached in other jurisdictions." Id. (citing State v. Morales, 10 P.3d 630 (Ariz. Ct. App. 2000); State v. Hart, 15 P.3d 917 (Mont. 2000); Pilot, 595 N.W.2d at 511; Whatley v. State, 509 S.E.2d 45 *651(Ga. 1998), cert. denied, 526 U.S. 1101; People v. Overlee, 666 N.Y.S.2d 572 (N.Y. App. Div. 1997)).
¶ 40. The majority's reliance on other jurisdictions is misplaced. None of the courts to which it cites considers the "purpose and effect" of the prosecutor's cross-examination in determining whether it is permissible. Instead, they either allow such questioning unequivocally, Whatley, 509 S.E.2d at 51, or allow it when the only possible explanation for the inconsistent testimony is deceit or when a defendant has opened the door by testifying about the veracity of other witnesses on direct examination. See Morales, 10 P.3d at 633; Pilot, 595 N.W.2d at 518; Hart, 15 P.3d at 924; Overlee, 666 N.Y.S.2d at 575.
¶ 41. There is good reason why no other jurisdiction has embraced the majority's test. Discerning the purpose behind a particular line of questions may prove more difficult in application than the majority acknowledges. In each case, judges will have to ask themselves: was this an attempt to bolster credibility or was this an attempt to impeach the defendant? These purposes, of course, are two sides of the same coin. Often they will both be at play, as the State concedes is apparent in the present case.
¶ 42. Highlighting inconsistencies in testimony may be accomplished by means other than asking one witness whether another witness is lying. While I acknowledge that some other questions, asked with certain inflections, may come close to that line, there is no doubt that the question here has crossed it.
¶ 43. If there is a saving grace to the majority opinion, it is that judges remain free to control the mode and order of interrogation and presentation. Wisconsin Stat. § 906.11 (2001-02) requires judges to exercise control of their courtrooms so as to (a) make *652the interrogation effective for the ascertainment of truth, (b) avoid needless consumption of time, and (c) protect witnesses from harassment.4 While under the majority's new test attorneys are not precluded from asking whether another witness is lying, circuit courts are not required to permit this mode of interrogation.
¶ 44. Even without a bright line rule prohibiting the "were they lying" question, judges should preclude this mode of interrogation under Wis. Stat. § 906.11 (2001-02) because a witness's opinion on another's credibility is irrelevant, and is often offered not to ascertain the truth but rather to harass. Even if it is deemed to be relevant, and thus have some probative value, it should be precluded under Wis. Stat. § 904.03 (2001-02) because such minimal value is substantially outweighed by the danger of misleading the jury or unfair prejudice.5
*653¶ 45. In the end, I view the majority's opinion as a step backwards in our pursuit of promoting civility in the courtrooms of this state. Although the majority's new test takes away a bright line rule, judges remain armed with the rules of evidence in order to exercise the appropriate control in their own courtrooms. Because I fear that the majority has opened the door to a line of questioning which invades the province of the jury, is of no probative value, and may prove misleading, I urge judges to use those rules to preclude these questions. Accordingly, I respectfully concur.
¶ 46. I am authorized to state that Chief Justice SHIRLEY S. ABRAHAMSON joins this opinion.
1ndeed, it appears that only two states have adopted an unequivocal rule that the question "Is the witness lying?" is proper. See Whatley v. State, 509 S.E.2d 45, 51 (Ga. 1998), cert. denied, 526 U.S. 1101; Fisher v. State, 736 A.2d 1125, 1162-63 (Md. App. 1999).
The United States Supreme Court reminds us that a prosecutor should prosecute with earnestness and vigor but "while he may strike hard blows, he is not at liberty to strike foul ones." Berger v. United States, 295 U.S. 78, 88 (1935).
As Johnson notes, there is nothing inherently inconsistent about his testimony, in context, as it relates to testimony given by the state's witness, Ms. Zahn. It is, for example, possible that Ms. Zahn asked him what he had in the bag. So, too, it is possible that he simply did not hear her. Under this analysis, neither Ms. Zahn nor Johnson would be lying.
Wisconsin Stat. § 906.11 (2001-02) provides in relevant part:
(1) CONTROL BY JUDGE. The judge shall exercise reasonable control over the mode and order of interrogating witnesses and presenting evidence so as to do all of the following:
(a) Make the interrogation and presentation effective for the ascertainment of the truth.
(b) Avoid needless consumption of time.
(c) Protect witnesses from harassment or undue embarrassment.
Wisconsin Stat. § 904.03 (2001-02) provides:
Although relevant, evidence may be excluded if its probative value is substantially outweighed by the danger of unfair prejudice, confusion of the issues, or misleading the jury, or by considerations of undue delay, waste of time, or needless presentation of cumulative evidence.
*653These rules of evidence referenced are not meant to be an exhaustive list but rather illustrative of rules that should be used to preclude the "were they lying" questions.