We granted certiorari to determine whether certain opinion testimony constituted rape trauma syndrome evidence and whether it was admissible in a criminal case. We decide that such testimony was not rape trauma syndrome evidence and was admissible under C.R.E. 701. Therefore, we affirm the decision of the court of appeals holding that such evidence was admissible and affirming the defendant’s convictions of first degree sexual assault and second degree kidnapping.
I.
The victim was approached by the defendant outside a Colorado Springs convenience store in the early morning on March 3, 1983. After several sexually suggestive remarks by the defendant, the victim attempted to get into her car. The defendant said “I guess I have to force you” and placed an unidentified object against the victim’s back. The defendant ordered the victim to get into the car and move over to the passenger seat or he would “blow [her] away right here.” The victim complied but tried to leave the car through the passenger door. The defendant grabbed the victim’s hair and poked a finger in her eyes. After further fruitless resistance by the victim, the defendant drove the car into a residential neighborhood, forcing the victim to remove her pants and underwear along the way. The defendant parked the car and sexually assaulted the victim. Afterward, the defendant told the victim that he shouldn’t have forced himself upon her and that he wanted to take her out for lunch to make up for doing so. Although the victim was not a student at Pikes Peak Community College, she told the defendant she was and agreed to meet him there for lunch. The defendant drove back to the convenience store, parked the car and left. The victim drove home and woke up her brother. The victim and her brother drove to their mother’s house after she told him what had happened. The police were called from the victim’s mother’s house and an officer met the defendant at Pikes Peak Community College later that day and arrested him.
The defendant claimed the victim had consented to sexual intercourse. At trial, during cross-examination of the victim, defense counsel implied that the victim had asked the defendant for help in starting her car, that she knew the defendant did not have a weapon, that she never tried to escape from the defendant and that she had consented to sexual intercourse.
*958Subsequent to the victim’s testimony, the People called Candy Hurst, a counselor employed by the Victim Services Unit of the Colorado Springs Police Department. Hurst testified.that she had counseled approximately thirty rape victims during her eighteen months with the Victim Services Unit and had interviewed the victim on the date of the assault. Hurst testified as to the victim’s demeanor at the time of the interview. She stated that the victim was in a state of shock and was confused as to the chronological order of events related to the assault. She expressed her opinion that these reactions were typical of victims of sexual assault and that the victim’s behavior was very consistent with being a rape victim. Hurst was not offered as an expert witness but she was cross-examined by defense counsel concerning her educational background and vocational training. Defense counsel’s objections to Hurst’s opinions were overruled.
The court of appeals held that, because the testimony in question involved observations of the victim unencumbered by scientific terminology and the witness did not opine that the victim had been raped, the testimony was not rape trauma syndrome evidence. People v. Farley, 712 P.2d 1116 (Colo.App.1985). Thus, the court upheld the trial court ruling admitting the testimony. The court of appeals relied upon C.R. E. 701 and C.R.E. 702 in so doing.
II.
We agree with the decision of the court of appeals that the testimony in question did not constitute rape trauma syndrome evidence.1 For the most part, this testimony was limited to observations of the victim’s demeanor. The witness did not elaborate upon the different stages indicative of rape trauma syndrome and, indeed, did not use the term “rape trauma syndrome.” While we recognize that certain testimony could easily amount to rape trauma syndrome evidence despite a failure to label it as such, we hold that this testimony was not rape trauma syndrome evidence. See State v. Huey, 145 Ariz. 59, 699 P.2d 1290 (1985) (psychiatrist’s testimony regarding rape victim’s mental state and that her mental state was consistent with the ordeal she described held admissible as general observations of stress rather than rape trauma syndrome evidence).
There was some confusion in the trial court proceedings regarding Hurst’s testimony. At an in camera session during the trial which occurred after Hurst testified, the trial court stated that it had accepted Hurst as an expert witness. The record does not bear out the court’s recollection. Hurst was neither offered nor accepted as an expert. At no point was the jury advised that she was an expert. For those reasons, we have treated Hurst as a lay witness and hold that her testimony was lay opinion testimony admissible under C.R.E. 701.
The witness offered her opinion, based upon her prior experience with rape victims, that the victim’s reactions were very consistent with being a rape victim. Under C.R.E. 701, a witness not testifying as an expert may present “opinions or inferences which are (a) rationally based on the perception of the witness and (b) helpful to a clear understanding of his testimony or the determination of a fact in issue.” The sufficiency of evidence to establish the qualifications and knowledge of a witness to express an opinion based on physical facts she has observed is a question for the trial court, not subject to reversal unless clearly erroneous. People v. Gallegos, 644 P.2d 920 (Colo.1982); Wise v. Hillman, 625 P.2d 364 (Colo.1981); Atencio v. Torres, 153 Colo. 507, 385 P.2d 659 (1963).
Gallegos also involved a sexual assault and is very similar to the case now before us. In his cross-examination of the victim, the defense counsel in Gallegos brought out the fact that the victim had giggled at the preliminary hearing. From this, he implied that the victim giggled or laughed throughout the proceeding and that she *959treated the case as a joke. To rebut these inferences, the prosecution called a sheriffs investigator who had investigated the case and had observed the victim at the preliminary hearing. He testified that the victim’s laughter was a nervous reaction, not a mockery of the proceeding, and that her demeanor was “very typical of a rape victim.” 644 P.2d at 927. We held that the investigator’s testimony was admissible under C.R.E. 701 and stated:
Smith [the sheriff’s investigator] observed the victim testifying at the preliminary hearing. At trial he stated a conclusion based on his sensory impressions from the preliminary hearing in conjunction with his prior knowledge and experience. That Smith based his conclusion in part on his experience as a police officer does not render his testimony inadmissible.
Since defense counsel sought to impeach the victim’s credibility through his questions on cross-examination, Smith’s testimony, intended to rehabilitate her credibility, was appropriate, and did not constitute impermissible bolstering.
644 P.2d at 928 (citations omitted). See also People v. Rubanowitz, 673 P.2d 45 (Colo.App.1983) (the trial court erred in refusing to permit an attorney who represented the defendant at a previous trial to express his opinion, as a lay witness, on the question of whether the defendant suffered from an impaired mental condition at the time of his alleged commission of the offense).
The Gallegos analysis is applicable to this case and, accordingly, the judgment of the court of appeals is affirmed.
LOHR, J., specially concurs. ERICKSON, J., dissents, and KIRSHBAUM, J., joins in the dissent.. This case, therefore, differs from People v. Hampton, 746 P.2d 947 (Colo.1987), in which we held that certain expert testimony regarding rape trauma syndrome was admissible. For an explanation of the syndrome, see Hampton.