Judge CRAWFORD
delivered the opinion of the Court.
Contrary to his pleas, appellant was convicted by a panel of officer and enlisted members of carnal knowledge; indecent acts with two children, K and J; communicating a threat; assault; and assault and battery, in violation of Articles 120, 134, and 128, Uniform Code of Military Justice, 10 USC §§ 920, 934, and 928, respectively. Appellant was sentenced to a dishonorable discharge, 12 years’ confinement, and reduction to the lowest enlisted grade. The Court of Criminal Appeals affirmed the findings and sentence in an unpublished opinion. We granted review of the following issues:
I. WHETHER THE MILITARY JUDGE COMMITTED PREJUDICIAL ERROR BY ALLOWING THE TWO ALLEGED VICTIMS TO TESTIFY BEHIND A SCREEN, IN VIOLATION OF APPELLANT’S CONSTITUTIONAL RIGHT TO CONFRONT HIS ACCUSERS, WHEN THERE WAS NO BASIS TO SUPPORT SUCH A RULING.
II. WHETHER APPELLANT WAS SUBSTANTIALLY PREJUDICED BY THE TESTIMONY OF THE GOVERNMENT EXPERT WITNESS, WHICH IMPERMISSIBLY BOLSTERED THE CREDIBILITY OF THE GOVERNMENT WITNESSES ACCUSING APPELLANT, BY CONCLUDING THAT THEY WERE TRUTHFUL AND GAVE THEIR ALLEGATIONS A “STAMP OF SCIENTIFIC LEGITIMACY” AS WELL AS IMPERMISSIBLY “PROFILING” APPELLANT AS A CHILD SEXUAL ABUSER.
III. WHETHER THE MILITARY JUDGE COMMITTED PREJUDICIAL ERROR BY INSTRUCTING THE MEMBERS THAT PRIOR STATEMENTS COULD BE CONSIDERED AS SUBSTANTIVE EVIDENCE WHEN THEY DID NOT MEET THE EXPRESS REQUIREMENTS OF MIL.R.EVID. 801(d)(1)(B) and UNITED STATES V. MCCASKEY, 30 MJ 188 (CMA 1990).
We resolve these issues against appellant for the reasons set forth below.
FACTS — ISSUE I
In February 1994, K testified in person during the Article 321 investigation. However, on June 7, 1994, the prosecutor requested to have both K and J testify either by closed-circuit television or out of appellant’s sight.
The defense objected to an ex parte evaluation by Dr. Linda Bessett, a licensed psychologist, of the girls’ ability to testify. The defense suggested an independent, court-appointed expert conduct this evaluation with defense presence at the interview or, in the alternative, that the interview be taped. The defense also requested that the military judge conduct an in camera interview of the girls to assess independently each girl’s emotional state. The military judge refused to prevent Dr. Bessett from conducting this interview, to permit the defense expert to be present, or to have the interview videotaped.
After the judge’s ruling, Dr. Bessett interviewed the girls with Ms. Diana Schofield, a government expert in child sexual abuse, as an observer. Dr. Bessett testified concerning the effect that testifying in the presence of appellant would have upon the victims. Dr. Bessett made specific recommendations concerning the parameters of that testimony. In ruling on the government request, the military judge made the following findings of fact:
[K] testified at the Article 32 investigation and viewed it as a very negative experience. The questions were confusing and it was a very long proceeding. [K] told Dr. Bessett that she was scared about the trial process and about being in the same room as the accused. Dr. Bessett believes it would be psychologically difficult for her to [148]*148testify in court and face the accused, but believes the accused [sic] could identify the accused in court and testify in his presence, as long as she did not have to look at him for a long period of time. Her anxiety level will be very high. Dr. Bessett’s professional opinion is that [K] could testify either behind a screen, or in a position where the accused was not in direct line of sight with her.
On 12 August 1994, Dr. Bessett separately interviewed [J] and her mother ... [who] reported her daughter was having nightmares again. [J] stated she was afraid the accused would kill her, having allegedly threatened to do so while the alleged abuse was occurring. In Dr. Bessett’s opinion, [J] is very scared of the accused, and would not be able to testify if she could see the accused. A tour of the court room did not help her, and her fear is overwhelming. She believes [J] could psychologically cope with identifying the accused from a picture, but she could not cope with identifying the accused in person. Dr. Bessett’s professional opinion is that [J] can testify under limited conditions because of her fear of the accused. Specifically, the preference would be for her to testify in a separate room with only a trial and defense counsel present and she could not see the accused or court members. Alternatively, she believes she may be able to testify behind a screen.
The military judge announced the procedure that would be used in light of his findings:
[K] will be allowed to testify facing away from the Accused, directly facing the court members. [J] will be allowed to testify facing the Trial Counsel. The closed circuit television camera will project their images to a television which will be positioned for the military judge, Defense Counsel, the Accused and Court Reporter to see. And, I note the way the t.v. is setup right now, I can’t see, but it appears I should be able to see the faces of the witnesses from where I’m sitting. A screen will not be set up for [K] unless it’s [sic] presence appears to become necessary. A screen will be positioned along the side of the witness box for [J], The witnesses may already be on the stand before the military judge and members come into the room. The Accused will be seated at the seat at the Defense Counsel table which is farthest away from the witnesses. Cross-examination of the witnesses will be done in such a position of the courtroom that the vision of the witnesses conforms with the spirit of this ruling. The witnesses will be instructed to speak up and to let the Court know when they need a break. Additionally, the witnesses will be allowed to have a victim witness representative sit next to them, but that person will be instructed beforehand not to give any cues or anything to the witnesses.
Further accommodation was directed so that the two defense counsel would have eye contact with each other to facilitate communication, and the military judge indicated that there would be latitude to permit counsel to communicate as needed. Defense counsel renewed his objection to the procedures as a denial of due process.
Prior to K taking the stand, the military judge gave the following instruction concerning the special measures taken to facilitate her testimony:
Members of the court, ... as you can see, a television monitor is being set up and there are video cameras in the courtroom. I have determined that the courtroom will be arranged in the manner that you see it. The witness will be seated in front of me here, facing you the court members with a closed-circuit video camera transmitting the picture of the child testifying on a television monitor so the defense and the Accused can see her face, because she will be facing away from them towards you. You are instructed that you may not draw any inference against or for either side based upon the way the courtroom is arranged during the testimony of [K], The decision to arrange the courtroom in this manner is one that I made. You should evaluate the testimony of [K] the same as all of the other witnesses, and not take into account the arrangement of the courtroom in evaluating any witnesses [sic] testimony. [149]*149I will later give you a more detailed instruction on the credibility of a witness. I again, specifically instruct you that you cannot and must not infer anything for or against either party based upon my decision to arrange the courtroom in this manner. Additionally, I would instruct everyone in the courtroom to not indicate in any way that anyone is behind the television screen that we have here. This applies to the spectators as well as the parties.
One additional accommodation was made after K was initially unable even to approach the witness stand:
However, having observed her walk into the courtroom, face the members, the Accused and all of the spectators, I make a finding of fact that she was unable to even approach the witness stand and had to leave the courtroom saying, under her breath, “I can’t do this,” or words to that affect.
The screen and television equipment were repositioned and appellant was asked to leave the room until K was seated. The defense concedes that the judge gave an instruction not to draw any inferences from the procedures being used.
DISCUSSION — ISSUE I
The Confrontation Clause of the Sixth Amendment provides that, “[i]n all criminal prosecutions, the accused shall enjoy the right ... to be confronted with the witnesses against him.” This is a fundamental right. Pointer v. Texas, 380 U.S. 400, 403, 85 S.Ct. 1065, 13 L.Ed.2d 923 (1965). “There are few subjects, perhaps, upon which this Court and other courts have been more nearly unanimous than in their expressions of belief that the right of confrontation and cross-examination is an essential and fundamental requirement for the kind of fair trial which is this country’s constitutional goal.” Id. at 405, 85 S.Ct. 1065.
The Confrontation Clause “reflects a preference for face-to-face confrontation at trial.” Ohio v. Roberts, 448 U.S. 56, 63, 100 S.Ct. 2531, 65 L.Ed.2d 597 (1980); see also Maryland v. Craig, 497 U.S. 836, 849, 110 S.Ct. 3157, 111 L.Ed.2d 666 (1990)(“a preference that ‘must occasionally give way to considerations of public policy and the necessities of the case’ ”)(quoting Mattox v. United States, 156 U.S. 237, 243, 15 S.Ct. 337, 39 L.Ed. 409 (1895)). Normally, the Confrontation Clause requires the defendant’s presence and ability to see the accusatory witnesses. Exceptions may be made. A second aspect of the Confrontation Clause is that the witnesses are under oath. A third is that the defendant has the right to have the finders of fact evaluate the demeanor of the witnesses. Fourth, the Confrontation Clause includes the right to cross-examine these witnesses. See California v. Green, 399 U.S. 149, 158, 90 S.Ct. 1930, 26 L.Ed.2d 489 (1970). While this right is fundamental, it is not absolute. Chambers v. Mississippi, 410 U.S. 284, 295, 93 S.Ct. 1038, 35 L.Ed.2d 297 (1973)(“Of course, the right to confront and to cross-examine is not absolute and may, in appropriate cases, bow to accommodate other legitimate interests in the criminal trial process.”). There are various interests that must be balanced against the defendant’s right of confrontation, including the Government’s “strong interest in effective law enforcement,” Roberts, supra at 64, 100 S.Ct. 2531, the state’s compelling “interest in the physical and psychological well-being of a minor victim,” Craig, supra at 852, 110 S.Ct. 3157, and the “societal interest in accurate factfinding.” Bourjaily v. United States, 483 U.S. 171, 182, 107 S.Ct. 2775, 97 L.Ed.2d 144 (1987).
The right of confrontation may yield to an important public policy when the reliability of the testimony at issue is otherwise assured. Maryland v. Craig, supra. In Craig, closed-circuit television was approved in a case involving a child victim where: “(1) there was a case-specific finding that testimony by the child in the presence of the defendant would cause the child to suffer serious emotional distress such that the child could not reasonably communicate; (2) the impact on the child would be ‘more than de minimis’-, (3) the child testified via one-way closed-circuit television, enabling the judge, jury, and defendant to observe the child’s demeanor during testimony; and (4) the [150]*150child was subject to full cross-examination.” United States v. Longstreath, 45 MJ 366, 372 (1996), citing Craig, supra at 856-57, 110 S.Ct. 3157. As illustrated in Longstreath, any deviations from the common form of confrontation must ensure the reliability of the evidence.
This Court has upheld various methods of obtaining testimony without face-to-face confrontation between an accused and a child victim. See United States v. Williams, 37 MJ 289 (CMA 1993)(child testified from a chair in the center of the courtroom); United States v. Thompson, 31 MJ 168 (CMA 1990)(children testified with their backs to the accused, but facing the judge and counsel); but see United States v. Daulton, 45 MJ 212 (1996)(accused excluded but permitted to observe the child through closed-circuit television). To support a determination to limit the right to face-to-face confrontation, the military judge must make a finding of necessity, i.e., that there is a likelihood that the child will suffer at least moderate emotional and mental harm if required to testify in the accused’s presence. See D.A.D. v. State, 566 So.2d 257 (Fla.App. 1990). This finding is a question of fact which “will not be reversed unless it is clearly erroneous or unsupported by the record.” Longstreath, supra at 373, citing United States v. Carrier, 9 F.3d 867, 870-71 (10th Cir.1993).
The military judge’s determination of necessity in the instant case is supported by the record. Dr. Bessett’s expert opinion provided a sound, adequate basis upon which the military judge considered whether each of the child victims could testify and under what circumstances each could communicate. When it became obvious that K could not even take the witness stand, the military judge had a clear basis upon which to modify his initial ruling and permit K to testify behind the screen. See Longstreath, supra at 373. The expert testimony and the military judge’s own observation thus permitted the judge to determine that the impact on the two girls was more than de minimis. The arrangement of televisions and screens was such that all parties could see each child testify, and the defense was able to conduct full cross-examination while maintaining communications amongst themselves and with appellant.
Under these circumstances, we hold that the military judge committed no error materially prejudicial to appellant’s substantial rights; nor was appellant improperly denied his right to face-to-face confrontation.
FACTS — ISSUE II
Appellant characterizes the testimony of the government expert on child sexual abuse, Ms. Schofield, as profile evidence which impermissibly labeled him as a child sexual abuser. He complains that the expert also impermissibly vouched for the truthfulness and credibility of the two child victims. Appellant acknowledges that he did not object to testimony which allegedly implied the girls were telling the truth or that sexual abuse had occurred. Nor, we note, did appellant object to the qualifications of Ms. Schofield or to any evidence from her which allegedly labeled him as a child sexual abuser.
Ms. Schofield described the elements of Child Abuse Accommodation Syndrome and explained that it was a pattern of behavior used to explain misleading and contradictory actions by child victims of abuse. Trial counsel then asked her to relate the facts of the case to the various elements of the syndrome. Ms. Schofield noted that appellant, as an adult and baby-sitter, “did have the power and he did have the access and did threaten, or allegedly threatened the children.” In discussing the element of delayed disclosure, Ms. Schofield noted that, when K “saw a car that resembled [appellant’s] in the housing area,” it was “very significant” and “scared her.” It is this testimony which appellant claims labeled him as a child'abuser and attempted to vouch for the credibility of the child victims.
Appellant further attacks this line of questioning because, by relating facts of this case as made known to her, Ms. Schofield was allegedly telling the members that the children were victims and they should be believed. Appellant asserts that, because Ms. [151]*151Schofield vouched for the credibility of the children and labeled appellant as a child abuser, this error was obvious and substantial. Further, because the primary issue was credibility, appellant urges that this was prejudicial error requiring corrective action.
DISCUSSION — ISSUE II
It is clear from the cases of this Court that an expert “can inform the jury of characteristics in sexually abused children and describe the characteristics the alleged victim exhibits.” United States v. Birdsall, 47 MJ 404, 409 (1998), quoting United States v. Whitted, 11 F.3d 782, 785 (8th Cir.1993). A qualified expert can also “summarize the medical evidence and express an opinion that the evidence is consistent or inconsistent with the victim’s allegations of sexual abuse.” Id. But the expert may not express an opinion on the “ultimate issue of sexual abuse.” Id. Nor can an expert serve as a human lie detector for the court-martial. As we stated in Birdsall, supra at 410, “testimony which is the ‘functional equivalent’ of an expert’s opinion that the victim' should be believed is inadmissible.”
Ms. Schofield did not opine that the children were, in fact, abused or that appellant did, in fact, commit the abuse. See United States v. Birdsall, supra; United States v. Harrison, 31 MJ 330 (CMA 1990). Ms. Schofield related the elements of the syndrome and indicated which elements were present, given the facts of this case. She explained why certain facts she had been provided were significant in the context of the syndrome.
Additionally, Ms. Schofield was not permitted to assert that the children were credible. See United States v. Birdsall, supra; Mil.R.Evid. 608(a), Manual for Courts-Martial, United States (1994 ed.).2 , When Ms. Schofield ventured into the area of credibility, the military judge sustained defense counsel’s objection. Upon further objection, the military judge immediately instructed the members as follows:
Members of the Court, you’re advised that only you the members of the Court determine the credibility of witnesses in what the facts of this case are. No expert, witness or other witness can testify that the alleged victim’s account of what occurred is true or credible, or that the expert believes that the alleged victims, or that the expert believes the alleged victims, [sic] or that a sexual encounter occurred. To the extent that you believed that Miss Schofield has testified or implied that she believes the alleged victims or that a crime occurred or that the alleged victims are credible, you may not consider this as evidence that a crime occurred or that the alleged victims are credible.
These actions by the military judge assured that impermissible evidence did not get to the members and that any perception that the expert was testifying about credibility or the actual commission of an offense was erased. Ms. Schofield’s testimony adhered to the permissible limits of expert testimony. See United States v. Suarez, 35 MJ 374 (CMA 1992).
We hold that the proffered testimony was permissible. Regardless, we hold that there was no plain error.
Because there was no objection to Ms. Schofield’s testimony, appellant may only prevail if there was plain error.
Plain error is a doctrine that “is to be used sparingly, solely in those circumstances in which a miscarriage of justice would otherwise result.” United States v. Strachan, 35 MJ 362, 364 (CMA 1992), quoting United States v. Fisher, 21 MJ 327, 328-29 (CMA 1986), quoting United States v. Frady, 456 U.S. 152, 163 n. 14, 102 S.Ct. 1584, 1592 n. 14, 71 L.Ed.2d 816 (1982). “To establish plain error, appellant must demonstrate: that there was ‘error’; that such error was ‘plain, clear, or obvious’; and that the error ‘affect[ed]’ appellant’s ‘substantial rights.’ ” United States v. Czekala, 42 MJ 168, 170 (1995), quoting [152]*152United States v. Olano, 507 U.S. 725, 732, 734, 113 S.Ct. 1770, 1777-78, 123 L.Ed.2d 508 (1993).
United States v. Hall, 46 MJ 145, 146-7 (1997).
Any error herein was not plain and substantial. United States v. Powell, 49 MJ 460 (1998). Appellant was categorized as an authority figure (baby-sitter and adult), not as a child molester. Such an obvious conclusion is harmless and. does not distort the fairness of this trial to such an extent that application of plain error is warranted.
Similarly, with respect to any contention that Ms. Schofield vouched for the credibility of the children, there is no plain error. Defense counsel’s objection was sustained and an instruction was given. Full relief was afforded to appellant in a timely manner. Thus, not only was any perceived error corrected on the spot, but any potential prejudice was eradicated.
Within this issue, appellant makes two other related assertions. First, he implies that Ms. Schofield was not qualified as an expert. This claim is easily disposed of. Ms. Schofield had specialized training and experience which would assist the trier of fact and clearly qualified her as an expert. Mil.R.Evid. 702. During voir dire, defense counsel inquired into Ms. Schofield’s qualifications and affirmatively stated that he had “no objections” to trial counsel’s offer of Ms. Schofield as an expert in child sexual abuse. Any claim that Ms. Schofield was not qualified was waived. Under the circumstances, there is obviously no plain error.
Next, appellant claims that Child Abuse Accommodation Syndrome did not meet the foundational requirements for the admissibility of scientific evidence. See Daubert v. Merrell Dow Pharmaceuticals, Inc., 509 U.S. 579, 113 S.Ct. 2786, 125 L.Ed.2d 469 (1993). Clearly, the military judge did not abuse his discretion in admitting this testimony. First, such evidence is admissible. See United States v. Birdsall, and United States v. Suarez, both supra. Second, failure to object waives this alleged defect. United States v. Johnson, 35 MJ 17, 22 (CMA 1992). Finally, under the circumstances, as noted above, there is no basis to invoke the plain error doctrine. We hold that there was no error that “materially prejudice^] the substantial rights of [appellant].” Art. 59(a), UCMJ, 10 USC § 859(a).
FACTS — ISSUE III
Appellant contends that the military judge erred when he instructed the members that they could consider several statements by K and J as prior consistent statements. The military judge’s instructions, in relevant part, were as follows:
You have heard evidence that the witness [K] made statements prior to trial that may be consistent with her testimony at trial, specifically, that the abuse began in the Summer of 1990; the bleeding happened in the living room; he put his private part in her private part; his threat that he would not allow her to play with [his daughter]; and she told [her friend] that he was doing stuff to her too. You have heard evidence that the witness [J] made statements prior to trial that may be consistent with her testimony at trial, specifically, that he put a knife to her neck; he threatened her with a gun; he threatened to kill her; he put a pillow over her face; and he touched her “boob” with his fingernail. If you believe that such a consistent statement was made, you may consider it for its tendency to refute the charge of improper influence or improper motives. You may also consider the prior consistent statement as evidence of the truth of the matters expressed therein.
When trial counsel requested this instruction and produced a list of statements which she wished to be included in the instruction, defense counsel objected primarily on the basis that Mil.R.Evid. 801(d)(1)(B) required that the statement “be offered at trial in rebuttal to a rebutted [sic] claim of recent fabrication, improper influence or motive.” Defense counsel noted that certain of these statements were “not offered in rebuttal to anything,” and that it was the defense, not the Government, which brought the statements out for the record.
[153]*153Appellant’s argument here is that these statements were not admitted as prior consistent statements and that, by instructing on them as such, the military judge erred to appellant’s prejudice by allowing the members to consider the statements as substantive evidence. The Government concedes that the military judge’s characterization of the statements as prior consistent statements was incorrect but asserts that the instruction that the members could consider the statements as substantive evidence was nonetheless correct. The Court of Criminal Appeals reached a similar conclusion, unpub. op. at 8, and we agree.
DISCUSSION — ISSUE III
None of the statements here were specifically admitted as prior consistent statements pursuant to Mil.R.Evid. 801(d)(1)(B). That rule applies to statements made prior to trial which are consistent with the witness’s testimony and which are “offered to rebut an express or implied charge against the declarant of recent fabrication or improper influence or motive.” In a typical scenario, the defense counsel would try to impeach a witness’s credibility, and the trial counsel would try to rehabilitate the witness’s credibility by introducing a prior consistent statement. See United States v. McCaskey, 30 MJ 188 (CMA 1990). The issue there would be whether the out-of-court statement was properly admitted.
That is not the scenario presented by this case, however. Here, the defense strategy, in part, was to show that K’s and J’s testimony was not credible and was the result of coaching by adults. As part of that strategy, defense counsel questioned the girls about statements they had made prior to trial and attempted to point out inconsistencies. In actuality, the defense ended up soliciting affirmations of their testimony. Thus, the statements in issue were, in large part, presented to the members by defense counsel. Having been presented as such, the statements were already substantive evidence which the members could consider for their truth if they chose to believe them.
The question before us, then, is whether or not the instruction otherwise prejudiced appellant by highlighting the statements for the members just prior to deliberations.
We review a challenge of instructional error using an abuse of discretion standard. United States v. Damatta-Olivera, 37 MJ 474, 478 (CMA 1993), cert. denied, 512 U.S. 1244, 114 S.Ct. 2760, 129 L.Ed.2d 875 (1994). A military judge “has substantial discretionary power in deciding on the instructions to give.” 37 MJ at 478. Based on the evidence presented in this case, we cannot say that the military judge abused his discretion by instructing the members on these statements.
The testimony of these young victims was a substantial part of the evidence presented in a strong ease. Statements such as, “He put his private part in my private part,” and, “He threatened me with a gun,” were likely to stand out in the members’ minds as they deliberated. The defense itself highlighted the testimony of these girls by attempting to impeach them with their own prior statements. Appellant should not now be allowed to retreat from that strategy because it was unsuccessful. Nor should appellant now be allowed to fault the military judge for that lack of success. Cf. United States v. Raya, 45 MJ 251, 254 (1996)(“Invited error does not provide a basis for relief.”); United States v. Schnitzer, 44 MJ 380, 384 (1996)(Everett, S.J. and Gierke, J., concurring in the result)(“[S]ince to a considerable extent the error was invited by the defense, I conclude that this accused is not entitled to relief.”); United States v. Johnson, 26 F.3d 669, 677 (7th Cir.1994); A.E. v. Independent School District No. 25, 936 F.2d 472, 476 (10th Cir.1991).
In addition, there were at least two statements to which defense counsel failed to object but which were ultimately included in the instruction: 1) “that the abuse began in the Summer of 1990,” and 2) “[K] told [her friend] that he was doing stuff to her too.”3 [154]*154Regardless of our analysis above, with regard to these statements, appellant has waived his challenge, Mil.R.Evid. 103, and we find no plain error. See Powell, 49 MJ 460.
The decision of the United States Air Force Court of Criminal Appeals is affirmed.