This is a review of an unpublished decision of the court of appeals affirming a judgment of conviction of the circuit court for Grant county, Honorable John R. Wagner, Circuit Judge. After a jury trial, Larry W. Friedrich (Defendant) was convicted of two counts of second-degree sexual assault in violation of sec. 940.225(2) (e), Stats.1
*5The parties on review have phrased the issues in terms of whether the trial court abused its discretion in refusing to admit or in admitting certain types of evidence, and have asked us to review the court of appeals’ affirming of most of these trial court rulings. This court will not ordinarily review a court of appeals’ decision in a criminal case where only the question of the proper exercise of a trial court’s discretion was before the court of appeals. State v. Outlaw, 108 Wis. 2d 112, 120, 321 N.W.2d 145 (1982). See also, State v. McConnohie, 113 Wis. 2d 362, 334 N.W.2d 903 (1983). Exceptions to this general rule have been made, however, as in Outlaw, where this court accepted for a review a case based on allegations by the state that the court of appeals in that case had imposed upon it an inappropriate burden of proof. Outlaw, 108 Wis. 2d at 120. The Outlaw court stated: “The burden of proof to be assumed by the parties under sec. 905.10(3)(b), Stats., proceedings is clearly a matter of statewide importance and would have an effect on numerous criminal, and some civil, cases in the future.” Id. (Emphasis added.)
This case was accepted, in part, because we found that it raised important issues regarding the admissibility of psychological evidence, particularly “psychological profile” evidence when offered by a defendant for the purpose of showing his or her own pertinent traits of character. In reaching these issues, we have followed the *6approach used by the parties and thus, in reviewing the correctness of the court of appeals’ conclusion that the trial court did not commit an abuse of discretion in refusing to admit the psychological profile testimony, we in effect review the same issue as reviewed by the court of appeals. Thus, the first issue is: 1) Did the trial court abuse its discretion in refusing to allow a psychologist to testify for the defense that the accused did not fit the “psychological profile” of known incestuous sex offenders?
On the question of the admissibility of prior sex crimes testimony, this court was asked to review the question of whether or not the court of appeals incorrectly held that there was no abuse of discretion in admitting prior sex crimes evidence. We viewed this as a request to look at prior cases by this court to determine whether or not the admissibility here of such testimony under the facts of this case amounted to an abuse of discretion. The case afforded the court an opportunity to lay down more definitive guidelines in future cases involving admissibility of prior sex crimes evidence. As with the “psychological profile” evidence, the prior sex crimes evidence involves a matter of substantial importance. For these reasons, a majority of this court decided to accept review in this case. Thus, the second and third issues are: 2) Did the trial court abuse its discretion in admitting testimony of other sex acts committed against the complainant and another young girl four and six years prior to the charged offense? 3) Did the trial court abuse its discretion in admitting testimony of an adult woman who testified that the Defendant sexually harassed her two years prior to the charged offense?
*7Having taken for review these issues, we also address a fourth issue raised by the Defendant: 4) Should a new trial be granted in the interest of justice?
We conclude that the trial court did not abuse its discretion in refusing to admit the “psychological profile” evidence since the trial court was never asked to address the question of whether the proffered evidence was admissible to show a pertinent character trait of the accused. We also conclude that the admission of the two prior sex acts with young girls did not constitute an abuse of discretion since the court could have reasonably determined that, when compared with the nature of the crimes for which Defendant was charged, the prior acts served to establish the existence of a general scheme or plan.
Defendant also claims prejudicial error in the admission of the testimony of an adult woman who was allegedly sexually harassed by the Defendant. We conclude this testimony was improperly admitted by the trial court, but its admission constituted harmless error since we also conclude that there is no reasonable possibility that the error contributed to the conviction.
On the basis of the foregoing, we conclude there has been no miscarriage of justice and we are persuaded that a new trial would not lead to a different result. We therefore deny the request for a new trial in the “interest of justice.” We affirm the court of appeals and uphold the convictions.
The Defendant was charged and convicted on two counts of second-degree sexual assault under sec. 940.225(2)(e), Stats., for acts committed against his fourteen-year old niece by marriage. Her testimony established that the assaults occurred on two separate occasions while she was babysitting for Defendant’s *8children. Defendant denied the sexual assaults and produced an alibi defense. He testified that he was working at a tavern on both nights that the assaults allegedly occurred.
At trial, defense counsel made as an offer of proof the testimony of a clinical psychologist, Dr. Thomas Sannito. Such offer took a question and answer form. On the basis of tests administered to Defendant by Dr. Sannito, as well as observations garnered from personal interviews with the Defendant, Dr. Sannito prepared what he called a “psychological profile.” He then compared Defendant’s psychological profile to the psychological profile of known “incestuous” sex offenders.2 Dr. *9Sannito stated that the Defendant’s psychological profile was “diametrically opposed or different from the profile established for incestuous fathers and sexual offenders.”
The trial court asked Dr. Sannito whether his conclusion that Defendant did not have a profile consistent with performance of the alleged sex offenses would be modified or changed if he were to assume that the Defendant had engaged in prohibited sex acts of a nature similar to the charged offenses with other individuals prior to trial. Dr. Sannito responded that, assuming the prior acts took place, he would then “entertain the idea that possibly, that what we have is a false negative. In other words, a person who absolutely doesn’t fit the profile at all, but who in fact is a person who committed these things and we missed it.”
After Dr. Sannito set forth the substance of his testimony, defense counsel proceeded to explain his reasons and justifications for offering the evidence. He stated that the witness was presented “as an expert with specialized knowledge, who has tested this Defendant and finds that he lacks certain psychological characteristics.” He argued that this finding “tends to corrobo*10rate the Defendant’s testimony that he did not do these acts,” and “tends to negate the complaining witness’ testimony that he did those acts.”
The state argued that the proffered testimony went to the matter of witness credibility, a matter reserved to the jury, and was therefore inadmissible.
Noting that the only reason that the testimony would be introduced would be to support the Defendant’s denial of guilt, the trial court concluded that to admit the evidence would result in a usurpation of the jury function of assessing witness credibility, and disallowed the testimony.
The court of appeals, using an abuse of discretion standard, concluded there was no error. The appeals court noted that expert opinion testimony concerning a general character trait of a Defendant may be admissible, but observed that admission of such testimony rests in the discretion of the trial court. The appeals court found that discretion had been exercised and that there had been a reasonable basis for the determination.
The parties have focused our attention on the matter of identifying the purpose for which the psychologist’s testimony was offered. At trial, defense counsel appeared to offer the evidence in order to support Defendant’s credibility and impugn the credibility of certain adverse witnesses. The District Attorney and the trial court both understood this to be the purpose of the evidence and defense counsel raised no objection to this characterization. Defense counsel made brief mention of secs. 907.02, and 907.04, Stats.,3 dwelling on the former, *11in order to emphasize that the psychologist could issue an expert opinion on these matters and that his opinions would assist the jury. On appeal, defense counsel argued that the testimony was offered for the limited purpose of establishing that the Defendant did not match the psychological profile of known incestuous offenders, and that the psychologist would not issue an opinion on Defendant’s guilt or innocence.
At oral argument, defense counsel maintained that he had clearly stated the purpose for introducing the testimony and that the opinion evidence fit within sec. 904.04(1)(a), Stats., as a character trait of the accused.4 The record does not support this assertion. He also stated that the testimony went to the credibility of both the Defendant and the accusing witnesses.
The parties have emphasized the applicability of sec. 904.04(l)(a), Stats., to this case. Section 904.04(1), *12states the general rule that character evidence is not admissible for the purpose of proving that the person acted in conformity therewith. Subsection (l)(a) outlines an exception to that rule, providing, in part, that an accused may introduce evidence of a pertinent character trait. The parties debate whether the proffered opinion testimony comes within the sec. 904.04(l)(a), exception as establishing a pertinent character trait of the accused, i.e., a character trait that would prevent him from committing incest.
In this case the trial court expressed concern over the effect that the introduction of the testimony would likely have on the jury. The trial court noted that the type of expert testimony sought to be introduced had the potential to cause the jury to substitute the expert’s opinions for its own, and concluded the evidence was inadmissible due to its likelihood to usurp the jury’s function in assessing witness credibility.5
The trial court did not have the opportunity to exercise its discretion on the question of whether the opinion evidence was admissible under sec. 904.04(l)(a), Stats. The mechanics of an offer of proof in our system of evidence places responsibility for stating the purpose of proffered evidence upon the party seeking to introduce the evidence. Here defense counsel had the burden *13of articulating the correct rationale for admitting the evidence, and did not direct the court’s attention to the proper statutory section.
The burden of setting forth the substance of the evidence in making an offer of proof is clearly stated in sec. 901.03(l)(b), Stats.6 Error may not be predicated on an evidence ruling if the proponent fails to apprise the judge of the substance of the evidence.
Placing the responsibility on the proponent of evidence for identifying the purpose for which the evidence is sought to be introduced, and the grounds for its admissibility, is consistent with our system of advocacy and with prior statements of this court on related evidence questions. In Haskins v. State, 97 Wis. 2d 408, 294 N.W.2d 25 (1980), this court dealt with a claim of error related to a trial court ruling limiting the scope of cross-examination of a witness. At trial, the prosecutor objected to questions put to the witness on the grounds of irrelevancy, and the trial court sustained the objection. This court upheld the ruling, stating: “Where no offer of proof was made with regard to any testimony excluded by the ruling, and where no explanation was given as to why defense counsel thought the question was material, no abuse of discretion can be found.” Id. at 422-423.
*14In Frankovis v. State, 94 Wis. 2d 141, 151-152, 287 N.W.2d 791 (1980), the defendant claimed that the trial court erred when two photographs of the robbery victim were admitted into evidence, in that they would evoke a sympathetic reaction toward the victim and hostility toward the defendant, from the jury. Defendant made an objection at trial, but not on these grounds. The court stated: “ ‘[A] specific objection overruled will be effective only to the extent of the ground specified.’ ” Id. at 152, quoting State v. Hoffman, 240 Wis. 2d 142, 152, 2 N.W.2d 707 (1942).
In State v. Becker, 51 Wis. 2d 659, 188 N.W.2d 449 (1971), this court faced an issue similar to the issue raised in Haskins, 97 Wis. 2d at 422-423. In Becker, the defense counsel argued the trial court erred when it ruled that twenty-seven questions asked of one witness were immaterial. Becker, 51 Wis. 2d at 666-67. The defense counsel declined at trial to make an offer of proof to show the materiality of the questions and also declined to explain the theory of the defense as an aid to ruling on the questions. Id. at 667.
The Becker court noted the general rule that where counsel fails to state the purpose of a question to which an objection is sustained on grounds of materiality, the trial court may exercise its discretion to exclude the evidence. Id. at 667. In explaining this rule, this court quoted favorably from McCormick:
“The reason for the requirement is that the judge must be fairly informed of the basis for the proponent’s claim of admissibility and the appellate court may understand the scope and effect of his ruling. To this end the statement must be reasonably specific, must state the purpose of proof offered unless that is apparent, and where the offered facts suggest *15a question as to their materiality or competency the offer must show the facts on which relevancy of admissibility depends.” McCormick, Evidence (Hornbook series), pp. 113, 114, sec. 51. Id. at 668.
In the instant case, as a direct result of defense counsel’s failure to properly identify the admissibility question as one related to character and not credibility, the trial court was unable to address that question. We have stated that: “Where a line of inquiry is sought to be justified on a theory no[t]... readily apparent... counsel owes it to the court to point out the proper reason for it, and on his failure to do so rejection of the evidence will not ordinarily be considered to warrant reversal.” Heims v. Hanke, 5 Wis. 2d 465, 471, 93 N.W.2d 455 (1958).
Even though the trial court did not exercise its discretion on the question of whether the proffered testimony constituted admissible evidence under sec. 904.04(l)(a), Stats., the trial court did exercise its discretion in excluding the testimony. We conclude that this exercise of discretion was proper.
Whether or not expert opinion should be admitted into evidence is largely a matter of the trial court’s discretion. Valiga v. National Food Co., 58 Wis.2d 232, 251-252, 206 N.W.2d 377 (1973). Whether opinion testimony of expert witnesses is properly received depends upon whether the members of the jury, having the knowledge and general experience common to every member of the community, would be aided in consideration of the issues by the testimony offered. Id. at 251. The expert testimony must assist the trier of fact. Section 907.02, Stats.
*16The trial judge found that the proffered testimony went to the matter of assessing witness credibility. The credibility of witnesses and the weight given to their testimony are matters left to the jury’s judgment. Shawver v. Roberts Corp., 90 Wis. 2d 672, 681, 280 N.W.2d 226 (1979). The credibility of a witness is ordinarily something a lay juror can knowledgeably determine without the help of expert opinion. State v. Haseltine, 120 Wis. 2d 92, 96, 352 N.W.2d 673 (Ct. App. 1984).
The trial judge could have reasonably determined that the jury could draw its own conclusions on the question of credibility, and concluded that the admission of such testimony was not only unnecessary, but improper. Valiga, 58 Wis. 2d at 251. In reviewing this decision, the question on appeal is not whether this court, ruling initially on admissibility of the evidence, would have permitted it to come in, but whether the trial court exercised its discretion in accordance with accepted legal standards and in accordance with the facts of record. State v. Wollman, 86 Wis. 2d 459, 464, 273 N.W.2d 225 (1979).
The trial judge’s ruling excluding the opinion evidence appears reasonable, especially given this court’s recent statement on psychiatric testimony:
“Although the majority of courts allow psychiatric testimony for impeachment purposes, the use of such testimony is generally limited to those cases where the witness whose credibility is in issue suffers from some physical or psychological disorder or defect which could interfere with his perceptual faculties or his ability to tell the truth.... Where the basis for the challenge of the witness’ credibility is *17not a physical or psychological disorder, however, the need for expert testimony is not recognized.” Hampton v. State, 92 Wis. 2d 450, 460, 285 N.W.2d 868 (1979). (Emphasis added.)
The trial judge had a reasonable basis for excluding the expert testimony and no abuse of discretion occurred.
Whether or not the proffered testimony would be admissible under sec. 904.04(1)(a), Stats., under the rationale expressed in King v. State, 75 Wis. 2d 26, 34-39, 248 N.W.2d 458 (1977), we need not decide because the attorney did not raise this issue. Cf., State v. Cavallo, 88 N.J. 508, 443 A. 2d 1020 (1982).
The State, over objection, introduced the testimonial evidence of M.A., J.H., and K.K. The trial court directed that this testimonial evidence was admissible on rebuttal, provided that the Defendant testified.7 The Defendant did testify and the testimony was admitted.
M.A. testified that she had been assaulted by the defendant. This alleged assault took place five years before trial and four years before the charged offenses occurred. M.A. testified that the Defendant picked her up from school in his car, and then pulled her pants down and touched her genital area. M.A. was ten years old at the time of this prior incident.
J.H.’s testimony recounted an occasion, seven years prior to trial, when she fell asleep while babysitting for Defendant’s children, and upon awakening encountered Defendant sitting beside her. She testified Defendant placed his hand inside her pants and told her to open or *18move her legs. J.H. was thirteen at the time of this incident.
K.K. testified that the Defendant had made sexual advances to her while she was employed as a bartender in the Defendant’s tavern in the spring of 1982. K.K. was twenty years old at the time of the trial, and 18 years old at the time of the alleged incidents.
The trial court admitted the testimony of M.A., J.H., and K.K. concerning these prior incidents, finding the evidence could show that Defendant had a “general scheme or motive” to obtain sexual gratification from young girls, and thus would be admissible under sec. 904.04(2), Stats.8
The court of appeals held that the prior-incident testimony of M.A. and J.H. was admissible to show a plan or motive under sec. 904.04(2), Stats., due to the similarities between the charged sexual misconduct and the other acts to which the complainant, M.A., and J.H. testified. The court described Defendant as having had a plan or motive to obtain sexual gratification from young girls with whom he had a quasi-familial relationship. It was found that the trial court’s ruling on these two witnesses had a reasonable basis, and that there had been no abuse of discretion in its admission.
However, the appeals court held that the trial court erred in admitting the testimony of K.K. since it was *19not probative of any plan or motive in common with that applicable to M.A. and J.H., or admissible under any other category under sec. 904.04(2), Stats. The court held this to constitute harmless error, however, since there was no reasonable possibility that the error contributed to Defendant’s conviction.
Defendant’s chief argument is that the other crimes evidence is inadmissible because it is remote in time, place, and circumstance. The State asserts that the evidence is admissible to show scheme or plan since the time gaps between the alleged incidents and the charged offenses do not reduce the probative value of the evidence.
Trial courts must apply a two-step test in determining whether other crimes evidence is admissible. State v. Danforth, 129 Wis. 2d 187, 202, 385 N.W.2d 125 (1986). First, the trial court must find that the evidence fits within one of the exceptions in sec. 904.04(2), Stats. Second, the trial court must exercise its discretion to determine whether any prejudice resulting from such evidence outweighs its probative value. Section 904.03. Implicit in the foregoing analysis is the requirement that the other crimes evidence is relevant to an issue in the case. Danforth, 129 Wis. 2d at 202.
An additional principle affects the exercise of trial court discretion as to rulings on evidence in sex crime cases involving children. This court has stated that a “greater latitude of proof as to other like occurrences” is evident in Wisconsin cases dealing with sex crimes, especially those dealing with incest and indecent liberties with a child. Hendrickson v. State, 61 Wis. 2d 275, 279, 212 N.W.2d 481 (1973). This “greater latitude of proof’ standard as applicable to other-acts evidence in *20sex crimes cases was recently reaffirmed by this court in State v. Fishnick, 127 Wis. 2d 247, 378 N.W.2d 272 (1985). The Fishnick court stated: “We reaffirm, however, our commitment to the principle that a greater latitude of proof is to be allowed in the admission of other-acts evidence in sex crimes cases, particularly in those involving incest and indecent liberties with a minor child.” Id. at 257. (Footnote omitted.)
The trial court found that the other-acts testimony of M.A. and J.H. fell within the “general scheme or motive” exceptions to sec. 904.04(2), Stats. We interpret the trial court’s use of the term “scheme” to mean “plan.” This finding denominates two exceptions under sec. 904.04(2), “plan” and “motive.”9 Having ascertained the specific exceptions under sec. 904.04(2), upon which the trial court relied, the next consideration on review is relevancy.10
*21The trial judge admitted the other-acts evidence, in part, because it was relevant to the issue of motive. In Fishnick, 127 Wis. 2d at 260-61, this court explained the relationship which motive, a specific type of exception to the general prohibition against character evidence listed in sec. 904.04(2), Stats., has to the elements of sexual assault under sec. 940.225, Stats. A defendant’s motive may show the reason why a defendant desired the result of the crime charged. Id. at 260.
Section 940.225(5) defines “sexual contact” as used in the statute.11 This definitional section, when taken together with the facts of this case, makes it clear that the elements of the crime that the state sought to convict the defendant of consisted of an intentional touching of the complainant’s genital parts for the purpose of sexually arousing or gratifying the defendant.
*22As in Fishnick, the motivation for defendant’s touching the complainant was sexual gratification. There was obviously a similar motive present in the prior incidents with M.A. and J.H. One of the elements of the charged crime was that the Defendant had the purpose of sexual arousal or gratification. Other acts evidence is admissible when probative of the elements of a crime, subject to the general rule excluding character evidence. Hough v. State, 70 Wis. 2d 807, 813, 235 N.W.2d 534 (1975).
Because the purpose of the sexual contact is an element of the crime, and because the Defendant’s motive is related to his purpose for committing the crime with which he is charged, other-acts evidence which tends to show Defendant’s motive is properly admissible. Fishnick, 127 Wis. 2d at 260-61. Thus the other-acts evidence consisting of the testimony of M.A. and J.H. is relevant since it illuminates Defendant’s motive, which in turn is related to his purpose for committing the crime — sexual gratification — which is an element of the charged offense.
The trial judge also found that the other-acts evidence was admissible to show a “plan,” within the meaning of sec. 904.04(2), Stats. As noted, the trial judge used the words “general scheme” when referring to the alternate ground for admissibility.
In Day v. State, 92 Wis. 2d 392, 284 N.W.2d 666 (1979), the defendant was charged with two counts of sexual intercourse with a child. Other-acts testimony from three non-complaining witnesses, all minors, was admitted. The evidence ruling was upheld. The court stated:
*23“Clearly this evidence tended to establish that the acts of sexual intercourse were all part of a definite, preconceived plan, design or scheme by the defendant. The testimony also establishes that the defendant created the opportunity and circumstances whereby the plan could be carried out. Because the testimony in question tends to establish existence of a preconceived plan and the opportunity to carry it out, the testimony was highly relevant and therefore admissible.” Day, 92 Wis. 2d at 405.
As illustrated in Day, reliance on the “plan” exception to sec. 904.04(2), Stats., requires that an inference be drawn. McCormick states that other-acts evidence sought to be introduced to establish the existence of a plan “will be relevant as showing motive, and hence the doing of the criminal act, the identity of the actor, or his intention.” McCormick, Evidence, (Hornbook series, 3d ed.) p. 559, sec. 190. While identity is not at issue in this case, the doing of the act and intent are at issue. Defendant has denied doing the act. Moreover, intent is an element of the crime. The other-acts testimony of M.A. and J.H. is thus relevant since the “plan” established by the facts of record relates to these contested issues of fact. The testimony in question, as in Day, tends to establish the existence of a plan, and is therefore highly relevant.
The trial court specifically found that the probative value of this evidence would outweigh its prejudicial effect. Our review of the trial court’s balancing of probative value and prejudicial effect under sec. 904.03, Stats., requires that we assess the other-acts referred to in the proffered testimony for their nearness in time, place, and circumstance to the alleged crime or element sought to be proved. Fishnick, 127 Wis. 2d at 261, citing Whitty *24v. State, 34 Wis. 2d 278, 294, 149 N.W.2d 557 (1967) cert. denied, 390 U.S. 959 (1968).
We find that the evidence of the two prior acts, as testified to by M.A. and J.H., was properly admissible since it was highly probative of a scheme or plan and this probative value outweighed any prejudicial effect. The other-acts testified to by M.A. and J.H. were quite similar to the charged offenses. These two prior incidents, as well as the charged crimes, share certain characteristics: All of these incidents involve young girls of like age; the girls were either part of the Defendant’s family or had a quasi-familial relationship with Defendant’s family; the nature of the sexual contact was virtually identical; Defendant was seen taking advantage of the girls in the context of relationship which involved an implied trust; and the Defendant was seen gratifying his sexual desires through the physical contact. The presence of these common elements serves to establish the existence of a scheme or plan within the meaning of sec. 904.04(2), Stats.
The Whitty case explains that this type of other-acts evidence “is admissible when such evidence is particularly probative in showing elements of the specific crime charged, intent, identity, system of criminal activity, to impeach credibility, and to show character in cases where character is put in issue by the defendant.” Whitty, 34 Wis. 2d at 292 (emphasis added). The facts of the instant case reveal that, at least with respect to the other-acts testimony of M.A. and J.H., the Defendant was involved in a system of criminal activity in seeking sexual gratification from young girls with whom he had a familial or quasi-familial relationship. The other-acts testimony was highly probative in this regard *25and was properly admitted for the purpose of establishing this “plan.”
Despite the time gaps in the present case, we conclude that the similarities among the prior incidents with M.A. and J.H. and the charged offenses are sufficient to sustain admissibility. We conclude it is unnecessary to establish any definite “cut-off’ point at which prior and present events are so removed in time from one another that the prejudicial effect always outweighs any probative value. The issue of remoteness as it relates to the balancing process in sec. 904.03, Stats., must be dealt with on a case-by-case basis.
Remoteness in time is a consideration when weighing probative value versus prejudicial effect. The farther removed the prior incident and charged offense are in time, the less probative is the prior incident. We find that the marked similarities among the prior incidents (with M.A. and J.H.) and the charged offenses overcome considerations arising due to remoteness in time. The trial court did not abuse its discretion in its sec. 904.03, Stats., balancing and had a reasonable basis for determining that the probative value of the M.A. and J.H. testimony outweighed any prejudicial effect.
Our conclusion that the M.A. and J.H. testimony is admissible is given further support by the “greater latitude of proof’ principle applicable in situations involving other-acts evidence in sex crimes. We note that this principle is particularly appropriate in both incest cases and cases involving indecent liberties with children.
Since we have found that the other-acts testimony of M.A. and J.H. was admissible to show a “plan” under sec. 904.04(2), Stats., we need not reach the second-step of the analysis to determine if the other-acts testimony of M.A. and J.H., as admitted under the “motive” *26exception, was more probative than prejudicial under sec. 904.03. Nevertheless, it is evident that many of the considerations here would have paralleled the analysis under “plan” and we conclude that the other-acts testimony would have also been admissible to show “motive.”
We find that the other-acts testimony of K.K., the adult woman, was inadmissible since it would have been more prejudicial than probative. As we stated in Fishnick, the type of legal prejudice with which we are concerned is the potential harm in a jury’s concluding that because an actor committed one bad act, he necessarily committed the crime with which he is now charged. Fishnick, 127 Wis. 2d at 261-62. K.K. testified that two years prior to the trial she was employed for a few months in Defendant’s tavern. K.K. was an adult at the time of her employment. K.K. stated that Defendant, on several occasions, made sexually provocative remarks to her, and tried to make sexual advances. The nature of this evidence is such that it does not fit within the outline of the scheme or plan established with respect to Defendant’s seeking sexual gratification from young girls. This other-acts testimony thus does not fit within the scheme or plan exception.
Nor does the testimony offered by K.K. fit within the “motive” exception to sec. 904.04(2), Stats. The motive sought to be established by introduction of the other-acts testimony centered around Defendant’s desire to obtain sexual gratification from young girls. The K.K. testimony showed that the Defendant sought a consensual sexual relationship with an adult.
The trial court abused its discretion in admitting K.K.’s testimony. However, we find this error to have *27been harmless. We conclude that there is no reasonable possibility that the error contributed to the conviction. State v. Dyess, 124 Wis. 2d 525, 543, 370 N.W.2d 222 (1985). We are convinced that the jury would have reached the same verdict relying solely on the untainted evidence which was presented at trial.
The dissent’s objection to the majority decision to uphold the Trial court’s admission of other crimes evidence in this case and its criticism of the “greater latitude” doctrine of the court are unpersuasive.
The “greater latitude” rule for admission of evidence of past offenses in sex crimes cases which has been part of the law of this State since Proper v. State, 85 Wis. 615, 55 N.W. 1035 (1893), brings down the judicial wrath of the author of the dissent. He states: “[n]o reasons are given because there are no reasons that withstand scrutiny. In every case, the ‘greater latitude’ concept is merely stated as a conclusion fitting the predilection of the court." (Emphasis added.) (At page 7.)
“Predilection” is described by Webster’s Ninth New Collegiate Dictionary, (1983) as: “ ... a strong liking deriving from one’s temperament or experience ... prejudice ... a feeling rooted in suspicion, fear, or intolerance ... bias_”
The zeal with which the dissent attacks the present majority and past position of this court would make the word “predilection” more applicable to the position espoused by the dissent than that of the majority.
To a person of normal, social and moral sensibility, the idea of the sexual exploitation of the young is so repulsive that it’s almost impossible to believe that none but the most depraved and degenerate would commit such an act. The average juror could well find it incom*28prehensible that one who stands before the court on trial could commit such an act.
Juries must have all the relevant facts before them. A past history of such a defendant’s plans, schemes and motives is relevant. Many judges in this State and a majority of this court have been aware for years of the need to place all relevant evidence in this type of case before the factfinder. That is a compelling reason for the “greater latitude” doctrine that the dissent ridicules when it declares such doctrine dissolves into a mere “predilection” on the part of judges to treat sexual exploitation crimes in the special manner the law recognizes as proper. It’s true as the dissent states that past acts of sexual abuse do show a “propensity”12 on the part of the Defendant, because without such “propensity” or “leaning,”13 the plan, scheme or motivation for it would never take place. But the plan, scheme and the motive behind the act to molest children is there as a fact and is in the exercise of judicial discretion clearly admissible, under sec. 904.04(2), Stats. The fact that the evidence also most certainly shows a propensity to commit such crimes should not deny its admission into evidence. There undoubtedly are some with a “propensity” to want sexual satisfaction from children who suppress *29their desires and commit no overt acts to bring such an unhealthy desire to fruition. Hence, they engage in no schemes or plans to actualize their morbid fantasy.
The purpose of the statute is to draw a distinction between a plan or scheme and a mere “propensity or leaning” toward some forbidden act. It is true that “the thought is father of the deed” but the thought does not always result in an act. Conscience, shame, fear of discovery keeps many anti-social thoughts or desires from being acted out. The law does not make thinking about adultery a crime, only the act itself is punished by our law. In this respect it differs from the more strict rule expressed in the Christian religion where the thought as well as the deed is forbidden.14
It is probably true that more people may be sexually attracted to children than actually carry out this “propensity” or “leaning.” But our statute makes admissible evidence of those past acts of sexual exploitation of children which demonstrate a scheme or plan. That scheme is to take advantage of the trust children show toward adults. Child exploiters take advantage of a child’s physical and emotional vulnerability in order to give gratification to their warped and perverted “propensities” and “leanings.” It is this scheme or plan to achieve sexual stimulation or gratification from the young, the most sexually vulnerable in our society, that allows trial courts in the exercise of discretion to admit evidence of past similar acts to show scheme or plan to exploit children.
*30The actions of child molesters and abusers may have a sameness because they are the plans and schemes that have proven most workable in achieving the result the molester or abuser seeks to obtain. A similar pattern of conduct is often the basis of apprehension of offenders.
Crimes like robbery, burglary and theft may be committed in an infinite variety of ways. Thus, courts scrutinize more closely the admissibility of past acts evidence when such crimes are charged. Juries need all pertinent admissible facts in order to arrive at a just verdict. In cases where an alleged child sexual abuser may have exploited other children, it would surely be contrary to the intent of our statute to say that only prior acts involving this one particular child victim for whose molestation he is being charged may be shown. Yet, this is the position which the dissent would have this court adopt. As phrased by the dissent:
“This writer would limit the Proper rule to a sex crime both involving the same victim and assailant and so close in time as to be a portion of a continuum of misconduct. Additionally, the ambience of the case should be such that it shows a relationship to the crime charged, i.e., Proper, even in its original form, does not conform to reasonable rules of evidence." (Dissent opinion at pages 43, 44, n. 3.)
We have correctly declared that where a defendant’s prior actions show a scheme or plan to exploit children such facts should be permitted to be shown if in the discretion of the trial judge the probative value of the evidence exceeds its prejudicial impact.
Because of immaturity, fear and embarrassment, sexually abused children find it difficult to testify. It is for this reason that much is being written of late about *31the necessity of support activities to make the taking of a statement less traumatic. Among these proposals are video taping their examinations and cross-examinations and allowing appropriate support persons to be present to make the ordeal of reliving and reciting their exploitation less difficult.
These are among the reasons why a more liberal admission of other crimes evidence is the rule in Wisconsin on sex crime cases.15 While it can be argued that *32they demonstrate a “propensity” they may also demonstrate a scheme, plan, motive, identity or other exception to the other crimes exclusionary rule.
Sexual abuse of children has become a serious problem:
“The sexual abuse of children is real and far more prevalent than most Americans are willing to believe. Approximately a half million American children will be sexually abused this year. Less than six percent of the incidents of child sexual abuse are ever reported to the police. Of the incidents reported, few ever go to trial. The majority of the. cases that are prosecuted are disposed of through plea bargaining, which usually means probation and some form of treatment for the offender. The plea bargain rarely gives adequate consideration to the plight of the child victim-witness. Further, contrary to popular belief, over fifty percent of these incidents of child sexual abuse involve violence, and yet less than one percent of known offenders ever go to prison.” Comment, Use of Videotaping to Avoid Traumatization of Child Sexual Abuse Victim-Witnesses, 21 Land & Water L. Rev. 565. (University of Wyoming, College of Law) (1986). (Footnotes omitted).16
*33The same author concludes: “The primary problem facing prosecutors in child sexual abuse cases is the difficulty in obtaining admissible evidence.”17 Id. at 566.
*34The permanent scars that the victims of child sexual abuse sustain are well documented and frequently described in the scientific literature and in the press. A very moving article on therapy support groups for adults who were the victims of incest in childhood and who find the memory and psychological burden difficult to bear appears in the Fall of 1986 issue of Victim’s Voice, Vol. 2, No. 3, p. 7, published quarterly by the Wisconsin Crime Victims Council and the Office of Crime Victim Services, Wisconsin Department of Justice, P.O. Box 7951, Madison, Wis. 53707.
Choosing to ignore this compelling statement of reason for the rule, the dissent tells us: “[i]n none... does the court ever articulate or explain any rationale for setting sex crimes, either generally or involving minors or blood relatives in particular, apart from all other crimes.... No reasons are given because there are no reasons...." (At page 7). (Emphasis added.)
The point of view espoused by the dissent equating the trial of a child sexual assault with that of forgery reflects a view of the law that is wrong and does not comport with sec. 904.04, Stats. Such a view does not reflect the reality of what is being faced by society in trying to cope with this problem. We must not and will *35not treat the sexual abuse of children as the dissent suggests when the dissent declares such offenses to be “a commonplace variety of criminal act....” (Dissent, at pages 51, 52). It is more than that. The consequences are too devastating and too lasting for such an approach to prevail.
But the dissent finds solace in what is apparently meant to be a broad overview of history: “[t]he evidence of the defendant’s alleged prior misconduct would fit almost every sexual assault upon minors that has been before this court... there is nothing new under the judicial sun." (Emphasis added.) (At page 51).
But the “judicial sun” is more useful when used to cast its light in the dark corners of this so easily hidden crime. The interpretations by this court have been in conformity to both the letter and spirit of the statute in question and promotes the ends of justice: punishment, deterrence, prevention and perhaps, hopefully, rehabilitation.
REQUEST FOR NEW TRIAL
Defendant has asked for a new trial in the interest of justice. “This court is reluctant to grant a new trial in the interest of justice and exercises its discretionary power only in exceptional cases.” State v. Cuyler, 110 Wis. 2d 133, 141, 327 N.W.2d 662 (1983). We do not find this to be an exceptional case.
There has been no showing of a miscarriage of justice, nor does it appear that a retrial under optimum circumstances will produce a different result. Id. at 142. We therefore deny Defendant’s request for a new trial.
*36By the Court. — The decision of the court of appeals is affirmed.
Section 940.225, Stats., provides:
*5“940.225. Sexual assault.... (2) SECOND DEGREE SEXUAL ASSAULT. Whoever does any of the following is guilty of a Class C felony:...
“(e) Has sexual contact or sexual intercourse with a person who is over the age of 12 years and under the age of 16 years.”
Dr. Sannito employed a definition of “incest” which was broad enough to incorporate the relationship in the instant case, where the victim was the niece of the Defendant, but only through marriage. He stated:
“I compared whether [Defendant] was similar or dissimilar to the sexual offenders and in particular incestuous fathers who are defined not just as people who have sexual relations with daughters but people who have sexual relations with any children in the family. ...”
Dr. Sannito also stated that “family” meant “extended family.”
Dr. Sannito’s definition of incest was not challenged, nor was the effect that the use of this definition had on the tests he administered gone into. We note the legal definition in Wisconsin is set forth in sec. 944.06, Stats:
“944.06 Incest. Whoever marries or has nonmarital sexual intercourse with a person he or she knows is a blood relative and such relative is in fact related in a degree within which the marriage of the parties is prohibited by the law of this state is guilty of a Class C felony.”
See also, sec. 765.03(1), Stats.:
“765.03 Who shall not marry; divorced persons. (1) No marriage shall be contracted while either of the parties has a hus*9band or wife living, nor between persons who are nearer of kin than 2nd cousins except that marriage may be contracted between first cousins where the female has attained the age of 55 years or where either party, at the time of application for a marriage license, submits an affidavit signed by a physician stating that either party is permanently sterile. Relationship under this section shall be computed by the rule of the civil law, whether the parties to the marriage are of the half or of the whole blood. A marriage may not be contracted if either party has such want of understanding as renders him or her incapable of assenting to marriage.”
The statutory definition of “incest” is thus much narrower than the definition employed by Dr. Sannito.
Sections 907.02 and 907.04, Stats., provide:
“907.02 Testimony by experts. 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 *11expert by knowledge, skill, experience, training, or education, may testify thereto in the form of an opinion or otherwise.”
“907.04 Opinion on ultimate issue. Testimony in the form of an opinion or inference otherwise admissible is not objectionable because it embraces an ultimate issue to be decided by the trier of fact.”
Defense counsel noted both of the foregoing sections in his offer of proof. While these sections provide for the use of expert opinion evidence, they do not dispose of the ultimate question of admissibility.
Section 904.04(l)(a), Stats., provides:
“904.04 Character evidence not admissible to prove conduct; exceptions; other crimes. (1) CHARACTER EVIDENCE GENERALLY. Evidence of a person’s character or a trait of his character is not admissible for the purpose of proving that he acted in conformity therewith on a particular occasion, except:
“(a) Character of accused. Evidence of a pertinent trait of his character offered by an accused, or by the prosecution to rebut the same;...”
The trial judge stated that the psychological profile testimony:
“[W]ill be coming in to show that Mr. Friedrich is not of the characteristic and profile that was used apparently in the studies in reaching a profile of rapists and incestuous individuals and child molesters. The only reason that would be coming in would be to back up Mr. Friedrich’s statement that no, he didn’t do it. Now, that would go directly to credibility and that’s just exactly what our courts have said should not be happening. You shouldn’t let the psychiatrists or the psychologists usurp the function of the jury on a question of credibility.”
Section 901.03, Stats., provides:
“901.03 Rulings on Evidence. (1) EFFECT OF ERRONEOUS RULING. Error may not be predicated upon a ruling which admits or excludes evidence unless a substantial right of the party is affected; and...
“(b) Offer of proof. In case the ruling is one excluding evidence, the substance of the evidence was made known to the judge by offer or was apparent from the context within which questions were asked.”
The trial court’s ruling that the other-acts testimony would not be admissible in the State’s case-in-chief was erroneous. Once the evidence was admissible under sec. 904.04(2), Stats., the evidence could have been introduced in the State’s case-in-chief. We find that the Defendant was not prejudiced by this error.
Section 904.04, Stats., provides:
“904.04 Character evidence not admissible to prove conduct; exceptions; other crimes_” (2) OTHER CRIMES, WRONGS, OR ACTS. Evidence of other crimes, wrongs, or acts is not admissible to prove the character of a person in order to show that he acted in conformity therewith. This subsection does not exclude the evidence when offered for other purposes, such as proof of motive, opportunity, intent, preparation, plan, knowledge, identity, or absence of mistake or accident.”
The State argues in its Brief that the trial court identified relevancy as to scheme or motive as one basis for admissibility; and that the trial court was using “scheme” and “motive” as synonyms. Although it is evident that many of the exceptions under sec. 904.04(2), Stats., tend to blend together, the “plan” and “motive” exceptions were specifically cited by the trial judge and deserve separate analysis.
Section 904.01, Stats., provides:
“904.01 Definition of “relevant evidence”. ‘Relevant evidence’ means evidence having any tendency to make the existence of any fact that is of consequence to the determination of the action more probable or less probable than it would be without the evidence.”
Implicit in the two-step analysis is that the other-acts evidence is relevant to an issue in the case. Before the court can engage in weighing probative value and prejudicial effect under sec. 904.03, Stats., a relevancy determination must be made. Section 904.03, provides:
*21“904.03 Exclusion of relevant evidence on grounds of prejudice, confusion, or waste of time. 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.” (Emphasis added.)
Section 940.225, Stats., provides:
“940.225 Sexual Assault_(5) DEFINITIONS. In this section: “(a) ‘Sexual contact’ means any intentional touching by the complainant or defendant, either directly or through clothing by the use of any body part or object, of the complainant’s, or defendant’s intimate part if that intentional touching is either for the purpose of sexually degrading; or for the purpose of sexually humiliating the complainant or sexually arousing or gratifying the defendant or if the touching contains the elements of actual or attempted battery under s. 940.19(1).”
“Propensity: An often intense natural inclination or preference syn see leaning.”
“Leaning: A definite but not decisive attraction or tendency syn LEANING, PROPENSITY, PROCLIVITY, PENCHANT mean a strong instinct or liking for something. LEANING suggests a liking or attraction not strong enough to be decisive or uncontrollable; PROPENSITY implies a deeply ingrained and usu. irresistible longing; PROCLIVITY suggests a strong natural proneness usu. to something objectionable or evil; PENCHANT implies a strongly marked taste in the person or an irresistible attraction in the object.” (Emphasis added.)
“You have heard that it was said ‘you shall not commit adultery.’ But I say to you that every one who looks at a woman lustfully has already committed adultery with her in his heart.” Mt 5:28 R.S.V.
We do not consider the Pennsylvania case cited by the Dissent (slip opinion at page 21), to be very persuasive. Close examination of Commonwealth v. Shively, 424 A. 2d 1257 (Pa. 1981) reveals that in overruling Commonwealth v. Kline, 361 Pa. 434, 65 A. 2d 348 (1949), wherein the Court set forth the more liberal evidence standard in sex crimes, the Shively court adopted the analysis set out in Commonwealth v. Boulden, 179 Pa. Super. 328, 116 A. 2d 867 (1955).
The Shively court did not consider it necessary to engage in any independent analysis. Rather, the court adopted wholesale the rationale espoused in a case written some twenty-six years earlier. Society today is more aware of the extent of child sex abuse and its effect on the young than was the case in 1955.
We also note that, of the six judges hearing the Shively case, only two were on the “majority” opinion. Two concurred in the result; one without explanation and one explaining the two incidents in question were not similar enough to permit admission of the prior crime. A dissenting opinion was written and joined in by another judge. The dissent summarized the details of the prior crime and the crime with which defendant was charged:
“I dissent. Six day [sic] after appellee’s release from prison where he was serving a three year term for forcible sodomy, he is again accused of forcibly raping and sodomizing another young girl. Both victims were approximately 20 years of age; both victims were in or entering their automobiles at the time they were approached by the perpetrator; both victims were forced with deadly weapons to accompany the assailant to a secluded country area; and both victims were ordered to assume crouching positions (one kneeling on all fours and one leaning over the front seat of an automobile) which *32exposed their genitalia from the rear for the assailant. In my opinion, the circumstances surrounding these crimes are sufficiently similar, and the time frame, considered in light of appellee's incarceration, sufficiently small, that appellee's conviction of the first offense was admissible at his trial for the second.
“Consequently, I would reverse the order of the Superior Court and affirm the judgments of sentence.” Shively, 424 A. 2d at 1260.
The gravity and extent of the problem of child sexual abuse has been well documented. Numerous Law Review articles on related studies have commented on the striking statistics. See, e.g., Note, The Testimony of Child Victims in Sex Abuse Prosecutions: The Legislative Innovations, 98 Harv. L. Rev. 806 (1985). (Citing survey *33results that one in five females and one in eleven males are sexually victimized as children; citing figures showing that reports of child sex abuse have increased 650% since 1976); Note, The Constitutionality of the Use of Two-Way Closed Circuit Television to Take Testimony of Child Victims of Sex Crimes, 53 Fordham L. Rev. 995 (1985).
A discussion of the national estimates and State of Wisconsin estimates of child sexual abuse appears in Sexual Abuse of Children: A Background Report, S.B. 80-19 Wisconsin Legislative Council Staff, pp. 4-11 (1980). This report notes the “wide variance” in estimates as to the extent of the problem on the national level. Analysts often employ different methodologies and definitions in their studies. There appears to be general agreement, however, both that the problem is serious, and that incidents of child sexual abuse are grossly under-reported.
Although state law now mandates the reporting of child sexual assault (i.e., violation of sec. 940.225, Stats.), the incidence of child sexual assault in Wisconsin is also under-reported.
In Whitcomb, Shapiro & Stellwagen, When the Victim is a Child: Issues For Judges and Prosecutors U.S. Dept, of Justice (1985), the authors, citing six studies on child sexual abuse based on retrospective self-reports of childhood experiences, concluded:
“Although these studies are not strictly comparable due to variations in definitions and research methodology, their findings suggest that anywhere from 12 to 38 percent of all women, and from three to 15 percent of men, are subject to some form of sexual abuse in their childhood.” Id. at 2-4.
There has been a great deal of recent discussion concerning efforts by state legislatures and courts to overcome some of the evidentiary obstacles. Two key areas have dealt with hearsay exceptions and the use of videotaped testimony. See, Note, Minnesota’s Hearsay Exception For Child Victims of Sexual Abuse, 11 Wm. Mitchell L. Rev. 799 (1985); Comment, Children’s Testimony in Sexual Abuse Cases: Ohio’s Proposed Legislation, 19 Akron L. Rev. 441 (1986); McGrath & Clemens, The Child Victim as a Witness in *34Sexual Abuse Cases, 46 Mont. L. Rev. 229 (1985); Note, A Comprehensive Approach to Child Hearsay Statements in Sex Abuse Cases, 83 Colum. L. Rev. 1745 (1983); Comment, Televised Testimony vs. The Confrontation Clause.... The Use of Videotapes in the Prosecution of Child Sexual Abuse, 23 Hous. L. Rev. 1215 (1986); Comment, Defendants’ Rights in Child Witness Competency Hearings: Establishing Constitutional Procedures for Sexual Abuse Cases, 69 Minn. L. Rev. 1377 (1985); See also, Comment, The Admissibility of “Child Sexual Abuse Accommodation Syndrome” in California Criminal Courts, 17 Pac. L. Journal 1361 (1986).