OPINION ON APPELLANT’S PETITION FOR DISCRETIONARY REVIEW
CAMPBELL, Judge.
A jury found appellant, Sharon Lee Emerson, guilty of the misdemeanor offense of driving while intoxicated. See Tex.Rev.Civ. Stat. art. 6701Z-l(b). The trial judge assessed punishment at 90 days confinement in the county jail, probated for two years, and a $500 fine. The Thirteenth Court of Appeals affirmed appellant’s conviction. Emerson v. State, 846 S.W.2d 531 (Tex.App.-Corpus Christi 1993). We granted appellant’s petition for discretionary review, pursuant to Texas Rule of Appellate Procedure 200(c)(2), to determine whether the court of appeals erred in holding that the trial court did not abuse its discretion by admitting results of the horizontal gaze nystagmus (HGN) test. We will affirm.
The relevant facts are not in dispute. Shortly before midnight on December 15, 1990, Corpus Christi police officer Arturo Trevino arrived at the scene of an automobile accident, where he observed an ambulance and two wrecked vehicles. Trevino noticed “a very strong odor of an intoxicating beverage” and ascertained that appellant was the driver of one of the vehicles involved in the collision. Trevino also noticed that appellant and her vehicle both smelled of alcohol. Upon inspecting appellant’s vehicle, Trevino [762]*762discovered an empty glass containing alcoholic residue. He also noted that the floorboards were wet and smelled of alcohol.
Trevino asked appellant to perform a number of sobriety tests at the accident scene. Appellant consented. Trevino first asked appellant to recite the alphabet. Appellant began with the letter “A,” jumped to “6” and then “Q,” then went back to “H,” and thereafter continued correctly. Trevino next asked appellant to count her fingers out loud, which she did correctly.
Trevino then administered the HGN test. Trevino testified at trial that appellant showed “all six clues” on the HGN test. Trevino also asked appellant to perform the “one-leg stand” and “walk and turn” tests, both of which she attempted but did not perform correctly. Based upon his observations at the accident scene and appellant’s performance on the various field sobriety tests, Trevino concluded that appellant was intoxicated.
At trial, Trevino described, both verbally and through visual demonstration, how he administers the HGN test in the field. He described how he moves an object horizontally in front of a suspect’s eyes while the suspect attempts to follow the object without moving her head. Trevino explained that he looks for a distinct “jerking movement” in the suspect’s eyes as she attempts to focus on the moving object. Trevino further explained that the “clues” for which he looks are: 1) the inability of the suspect to follow the object smoothly with her eyes; 2) a pronounced “jerking” of the suspect’s eyeball when the object is moved to the extreme corner of the suspect’s vision; and 3) an initial “jerking” of the suspect’s eyeball at an angle of vision of less than 45 degrees. Trevino statéd that he examines each of the suspect’s eyes, for a possible total of six clues in all.
Trevino testified that he had been a police officer with the Corpus Christi Police Department for two and a half years and had previously been with the Bexar County Sheriffs Department for approximately one year. He received training in the detection of intoxicated persons both in Bexar County and at the Corpus Christi Police Academy. He received further training at a three-day “state school” in Bexar County. At this “state school,” Trevino was introduced to a battery of field sobriety tests advocated by the National Highway Traffic Safety Administration (NHTSA), a division of the United States Department of Transportation. He learned how to administer the HGN test as part of this training. Trevino testified that he had been certified by the State of Texas to administer the HGN test, in addition to the other tests that comprise the three-test battery. Nothing in the record indicates that Trevino had received medical or scientific training in the effects of alcohol on human eye movement.
Appellant testified that she hit her head on her car windshield as a result of the collision. Appellant also testified that she consumed wine prior to the accident. Appellant stated that she did not remember clearly much of what occurred on the night of the collision.
The Corpus Christi Court of Appeals held that the trial court did not abuse its discretion by allowing Trevino to testify as an expert concerning the HGN test. The court of appeals eited Finley v. State, 809 S.W.2d 909 (Tex.App.-Houston [14th Dist.] 1991), and Lancaster v. State, 772 S.W.2d 137 (Tex.App.-Tyler 1988) in support of its holding. The courts of appeals in Finley and Lancaster held that testimony by a police officer concerning a defendant’s performance on the HGN test is admissible as lay opinion testimony on the issue of whether a defendant is intoxicated. Finley at 914; Lancaster at 138-39.
Appellant now argues that the court of appeals erred in holding that the results of the HGN test were admissible at her trial. Appellant makes two arguments. First, appellant argues that the HGN test is a “scientific” test, similar to a breathalyzer test, and that the HGN test results should not have been admitted because Officer Trevino was not qualified as a scientific expert. Second, appellant argues that the trial court erred in admitting the HGN evidence since the court failed to determine the reliability of the HGN test pursuant to Kelly v. State, 824 S.W.2d 568 (Tex.Crim.App.1992).
[763]*763The State makes two arguments in response. First, the State argues that Trevino’s testimony concerning the HGN test was admitted properly, since it was merely “opinion testimony,” in that Trevino used the HGN test results merely to support his “opinion” that appellant was intoxicated. Second, the State argues that Trevino was qualified as an expert to testify concerning the HGN results, since he was trained and certified by the State of Texas to administer the test.
The State Prosecuting Attorney argues that it is unnecessary for a law enforcement officer to be qualified as a “scientific” expert if the subject matter of the officer’s testimony is not “scientific” but merely “specialized” in nature. According to the State Prosecuting Attorney, Texas Rule of Criminal Evidence 702 contemplates different standards of scrutiny for qualification of experts for purposes of testimony on “scientific” and “specialized” topics. The State Prosecuting Attorney argues that, if a trained and experienced police officer testifies as to the results of an HGN test “merely to corroborate or explain the basis of his opinion that the defendant was intoxicated,” the officer’s testimony is of a “specialized” nature. If, however, the officer testifies as to the test subject’s exact blood alcohol content (BAC) based on the HGN test results, the State Prosecuting Attorney argues, then the officer’s testimony is “scientific.” The important consequence of the “scientific” versus “specialized” distinction, according to the State Prosecuting Attorney, is that, if the HGN evidence is offered in the former context, the proponent of the HGN evidence should demonstrate both: “1) ... the scientific validity of estimating BAC based upon HGN test results, and 2) ... that the officer is qualified to make such a correlation.” If, instead, the HGN evidence is offered as “specialized” testimony, the State Prosecuting Attorney argues, then the proponent of the HGN evidence need only show that “the officer was ... competent to administer and interpret the test....”
I. Novel Scientific Evidence
We will proceed with an analysis of the issues and arguments presented. Due to the nature of the HGN test, we disagree with the State’s assertion that HGN test results should be admissible as mere opinion testimony of a police officer. We have held previously that lay opinion testimony by a police officer generally is admissible to prove a defendant’s intoxication. Vaughn v. State, 493 S.W.2d 524, 525 (Tex.Crim.App.1972). However, the HGN test is based on a scientific theory. We have not determined whether that theory or the technique employed in the HGN test is reliable. We will therefore consider testimony concerning the HGN test as novel scientific evidence, just as we considered DNA evidence in Kelly v. State, 824 S.W.2d 568 (Tex.Crim.App.1992).
The admissibility of novel scientific evidence is governed by Texas Rule of Criminal Evidence 702, which addresses the admissibility of expert testimony. Rule 702 states:
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 expert by knowledge, skill, experience, training, or education, may testify thereto in the form of an opinion or otherwise.
The threshold determination in an inquiry into the admissibility of expert testimony under Rule 702 is whether such testimony is helpful to the trier of fact. Pierce v. State, 777 S.W.2d 399, 414 (Tex.Crim.App.1989). For such testimony to be helpful, the basis of the testimony must be reliable. Kelly v. State, 824 S.W.2d at 572. If novel scientific evidence is found to be reliable, it may still be determined unhelpful for some other reason. Id. The evidence may be unhelpful, even though reliable, if its probative value is substantially outweighed by, e.g., the risk of unfair prejudice, confusion of the issues, misleading the jury, undue delay, or the presentation of cumulative evidence. Id.; see also Tex.R.Crim.Evid. 403.
To be considered reliable, evidence based on a scientific theory must satisfy three criteria: 1) the underlying scientific theory must be valid; 2) the technique applying the theory must be valid; and 3) the technique must have been applied properly on the occasion in question. Id. at 573. We [764]*764have recognized the following non-exclusive list of factors which could affect a court’s determination of reliability: 1) the extent to which the underlying scientific theory and technique are accepted as valid by the relevant scientific community, if such community can be ascertained; 2) the existence of literature supporting or rejecting the underlying scientific theory and technique; 3) the clarity with which the underlying scientific theory and technique can be explained to the court; 4) the potential rate of error of the technique; 5) the availability of other experts to test and evaluate the technique; 6) the qualifications of the expert(s) testifying; and 7) the experience and skill of the person(s) who applied the technique on the occasion in question. Id.
Testimony concerning the HGN test, though not as complex as testimony concerning breathalyzer or DNA testing, is nevertheless scientific evidence, since it is based on a scientific theory, that alcohol affects human eye movement. The HGN test therefore must satisfy the three requirements set forth in Kelly in order to be admissible under Rule 702.
In order for testimony concerning the results of the HGN test to be admissible, it must first be shown, pursuant to Kelly, that the theory underlying the HGN test and the technique employed in its administration are both reliable. The State’s argument that testimony concerning the HGN test may be admitted as evidence of a “specialized,” as opposed to a “scientific,” nature under Rule 702 overlooks the need for proof of the reliability of the test.
II. Reliability of HGN Test
(a) Judicial Notice
We now inquire into the reliability of the HGN test, both as to the underlying scientific theory and technique. In Kelly, the trial court conducted a pre-trial hearing to determine whether the DNA evidence was admissible under Rule 702. Kelly, 824 S.W.2d at 569-71. We concluded in Kelly that the trial court’s decision to admit the DNA evidence was reasonable under Rule 702, given the evidence presented at the pre-trial hearing. Id. at 574. In the instant case, however, the trial court made no such inquiry concerning the admissibility of the HGN evidence pursuant to Rule 702, either before or during appellant’s trial. Therefore, we now inquire into the reliability of the HGN test pursuant to the doctrine of judicial notice. See Grice v. State, 142 Tex.Crim. 4, 151 S.W.2d 211 (App.1941); see also P. Giannelli & E. Imwinkelried, Scientific Evidence § 1-2 (1993); J. Weinstein & M. Berger, Weinstein’s Evidence ¶ 200[05] (1993); J. Strong, ed., McCormick on Evidence § 330 (1992).
We are authorized to take judicial notice of any scientific fact which “is capable of accurate and ready determination by resort to sources whose accuracy cannot reasonably be questioned.” McCormick on Evidence at § 330. The concept of judicial notice extends to scientific techniques and principles. See Grice, 151 S.W.2d 211; McCormick on Evidence at § 330; Giannelli & Imwinkelreid, Scientific Evidence at § 1-2.
Once a scientific principle is sufficiently established, a court may take judicial notice of the validity of that principle. Similarly, a court may take judicial notice of the validity of the technique applying that principle. In either case the effect is the same: judicial notice relieves the offering party of the burden of producing evidence on these issues.
Giannelli & Imwinkelreid, Scientific Evidence at § 1-2.
In making inquiry into the reliability of the theory underlying the HGN test and the technique, we take judicial notice of legislative facts.
Legislative facts are those which help the tribunal to determine the content of law and policy and to exercise its judgment or discretion in determining what course of action to take. Legislative facts are ordinarily general and do not concern [only] the parties.
Weinstein & Berger, Weinstein’s Evidence at ¶200[03]. By examining scientific articles outside the record of the instant case, we can determine what course of action to take with [765]*765regards to the reliability of the HGN test.1 The facts contained in those scientific articles do not concern only the parties to the instant case, and are therefore “legislative facts” ■within the context of this opinion.
In contrast to legislative facts are adjudicative facts. Adjudicative facts are “facts about the particular event which gave rise to the lawsuit and, like all adjudicative facts, ... [help] explain who did what, when, where, how, and with what motive and intent.” McCormick on Evidence at § 828. The scope of Texas Rule of Criminal Evidence 201 is limited to judicial notice of adjudicative facts. See Tex.R.Crim.Evid. 201.
Judicial notice, both of adjudicative and legislative facts, may be taken on appeal. See Chapa v. State, 729 S.W.2d 723, 728 n. 3 (Tex.Crim.App.1987); Grice v. State, 142 Tex.Crim. 4, 151 S.W.2d 211; see also McCormick on Evidence at § 333.2 As we noted in Chapa, “[t]hat the [judicially-noticed fact] was neither proven nor judicially noticed below is of no moment.” Chapa, 729 S.W.2d at 728 n. 3. According to one commentator:
The taking of judicial notice of a fact outside the record is part of the inherent power and function of every court, whether a trial or appellate tribunal. Whether an appellate court will take judicial notice of a fact on appeal which was not noted by the trial court, or called to that court’s attention, rests largely in the discretion of the appellate court.
G. Currie, Appellate Courts Use of Facts Outside of the Record by Resort to Judicial Notice and Independent Investigation, 1960 Wis.L.Rev. 39. Therefore, our status as an appellate court does not prevent us from inquiring into the general validity of the HGN test and the theory upon which it is based.
(b) Analysis
Nystagmus is defined as an “involuntary rapid oscillation of the eyeballs in a horizontal, vertical, or rotary direction.” R. Berkow, ed., The Merck Manual of Diagnosis and Therapy 1429 (1992). Horizontal gaze nys-tagmus is a variety of nystagmus that occurs when an individual’s eyes are deviated to the lateral extreme. V. Tharp et al., Nat’l Highway Traffic Safety Admin., U.S. Dep’t Transp., Development and Field Test of Psy-chophysical Tests for DWI Arrest 82 (1981); see also C. Rashbass, Barbiturate Nystag-mus and the Mechanisms of Visual Fixation, 183 Nature 897-98 (1959). Smooth pursuit eye movements are “slow, conjugate movements that enable the eyes to maintain a clear view of an object moving across the visual field.” J. Stapleton et al., Effects of Alcohol and Other Psychotropic Drugs on Eye Movements: Relevance to Traffic Safety, 47 J. Stud, on Alcohol 426, 427 (1986).
[766]*766The effect of alcohol on nystagmus, specifically HGN, is well-documented.3 See Id.; G. Good & A. Augsburger, Use of Horizontal Gaze Nystagmus as a Part of Roadside Sobriety Testing, 63 Am. J. Optometry & Physiological Optics 467, 467 (1986); I. Lehtinen et al., Acute Effects of Alcohol on Saccadic Eye Movements, 63 Psychopharmacology 17, 21 (1979); Stapleton et al, Effects of Alcohol and Other Psychotropic Drugs at 427-28; G. Goding & R. Dobie, Gaze Nystagmus and Blood Alcohol, 96 Laryngoscope 713, 713 (1986). Consumption of alcohol has also been found to effect smooth pursuit. See I. Wilkinson et al., Alcohol & Human Eye Movement, 97 Brain 785 (1974); Lehtinen et al., Quantitative Effects of Ethanol Infusion at 74; Stapleton et al., Effects of Alcohol and Other Psychotropic Drugs at 427. Nystag-mus may also be caused by factors other than alcohol, such as other drugs, neurological disorders, or brain damage. Goding & Dobie, Gaze Nystagmus and Blood Alcohol at 716; see also R. Leavitt, Horizontal Gaze Nystagmus, Voice for the Defense, Vol. 22, No. 9, at 17, 18-19 (1994).
The HGN test was developed in the late 1970’s by researchers at the Southern California Research Institute. See Tharp et al., Development and Field Test. The Institute developed a sobriety test battery consisting of three tests: the HGN, the walk and turn, and the one-leg stand. Id. NHTSA has since concluded that the HGN test is the single most effective field sobriety test in determining whether an individual is alcohol-impaired. Nat’l Highway Traffic Safety Admin., U.S. Dep’t Transp., Improved Sobriety Testing 1 (1984).
The pamphlet used in Texas to train officers to administer the HGN test is DWI Detection and Standardized Field Sobriety Testing (1992), published by NHTSA. According to that pamphlet, an officer must look for the following three criteria in the HGN test: 1) an inability to pursue smoothly an object, or stimulus, moving sideways across the suspect’s field of vision; 2) distinct, or pronounced, nystagmus at the eye’s maximum horizontal deviation; and 3) an angle of onset of nystagmus of less than or equal to 45 degrees. DWI Detection at VHI-13. The officer must look for these criteria in each eye, for a total of six “clues.” Id. at VIII-15. In order to ascertain the existence of these clues, the officer moves a stimulus, such as a pen light, in front of the suspect’s eyes. If the officer identifies four or more clues, then the officer classifies the suspect as intoxicated. Id. The testing procedure also calls for the officer to screen the suspect for factors such as corrective lenses, brain damage, medical disorders, or blindness, which could lead potentially to an incorrect determination as to whether the suspect is intoxicated. Id. at VIII-14 — -VIII-15.
In Texas, police officers must complete an NHTSA-approved, State-sponsored training course to be certified to administer the HGN test and the other two tests comprising the sobriety test battery. Texas Commission on Law Enforcement Officer Standards and Education (TCLEOSE), DWI Detection and Standardized Field Sobriety Testing Practitioner Certification Requirements (1991) (on file with Texas Engineering Extension Service, Law Enforcement Training Division). The 40-hour course consists of 24 hours of classroom instruction and 16 additional hours of field evaluations. Id. Upon satisfactory completion of the classroom instruction, an officer receives “practitioner certification” to administer the sobriety test battery. During the 16 hours of field evaluation, the officer must complete and document 35 test cases of administration of the test battery. Id. After completion of the 35 test cases, submission of the results, and approval by the Texas [767]*767Engineering Extension Service, Law Enforcement Training Division, an officer receives “proficiency certification” from TCLEOSE. Id.
The accuracy of the HGN test has been estimated at various levels, depending on such factors as testing conditions and the ability and experience of those conducting the test. The United States Department of Transportation estimates that a properly-trained police officer should be able to classify correctly, with respect to legal intoxication, 77% of his test subjects if the officer classifies subjects who score four or more points on the test as legally intoxicated. Improved Sobriety Testing at 4. Estimations of the accuracy of the HGN test have ranged as high as 88% under optimal conditions. See Tharp et al., Development and Field Test at 72.4 Most commonly, however, use of the HGN test, by itself, has been found to result in a correct determination of intoxication approximately 77% of the time. See Good & Augsburger at 468. When the results of the HGN test are considered in conjunction with the walk and turn test, the accuracy of the HGN test is enhanced to approximately 80% correct classification of test subjects. See Improved Sobriety Testing at 1.
NHTSA has also produced a formula by which it maintains that HGN results may be used to determine a suspect’s BAC through correlation of the angle of onset of nystag-mus to a BAC level. Tharp et al., Development and Field Test at 29.5 Aceordmg to the results of a lab test conducted by the NHTSA researchers, however, estimations of BAC based on the angle of onset of nystag-mus, using the NHTSA formula, varied by .03%, on the average, from the actual BAC. Id. at 62.6
(c) Other Jurisdictions
A number of courts from other jurisdictions have considered the merits of the HGN test and the admissibility of its results in DWI prosecutions. In State v. Superior Court, 149 Ariz. 269, 718 P.2d 171 (1986), the Supreme Court of Arizona held: 1) the results of the HGN test could be used to establish probable cause to arrest a suspect for DWI and 2) the scientific principles underlying the HGN test and the technique used in the test both were reliable, in that they satisfied the standard of “general acceptance in the relevant scientific community.” See Frye v. United States, 293 F. 1013 (D.C.Cir.1923); Kelly v. State, 824 S.W.2d 568 (Tex.Crim.App.1992).7 The Arizona court also held that HGN test results were admissible in a DWI prosecution only to corroborate the accuracy of chemical test results when those results had been challenged by the defendant.8 Finally, the court held that HGN results were not admissible, under any [768]*768circumstances, as independent evidence to quantify BAC. State v. Superior Court, 718 P.2d at 182.
In State v. Bresson, 51 Ohio St.3d 123, 554 N.E.2d 1330, 1334 (1990), the Ohio Supreme Court determined that the HGN test was a reliable indicator of BAC, and that HGN results were admissible “so long as the proper foundation has been shown both as to the officer’s training and ability to administer the test and as to the actual technique used by the officer in administering the test.” The court then opined that “although results on an HGN test may be admissible at trial by a properly trained officer, such an officer may not testify as to what he or she believes a driver’s actual or specific BAC level would be, based solely on the HGN test results.” Id. at 1336.
At least one court has decided that the HGN test is a reliable indicator of intoxication under the standard provided by Federal Rule of Evidence 702.9 State v. Murphy, 451 N.W.2d 154 (Iowa 1990); see also State v. Clark, 234 Mont. 222, 762 P.2d 853 (1988). In State v. Murphy, the Supreme Court of Iowa could find “no reason to question the reliability of the [HGN] test....” Murphy, 451 N.W.2d at 158. The court concluded that “testimony by a properly trained police officer with respect to the administration and results of the [HGN] test is admissible without need for further scientific evidence.” Id.
Other courts, when addressing the reliability of the HGN test as an issue of first impression, have classified HGN evidence as novel scientific evidence and have left the issue of the reliability of the HGN test to the trial courts. See State v. Witte, 251 Kan. 313, 836 P.2d 1110 (1992); State v. Barker, 179 W.Va. 194, 366 S.E.2d 642 (1988). In Witte, the Supreme Court of Kansas held that HGN results were scientific evidence, and as such would have to satisfy the Frye standard for admissibility. Witte, 836 P.2d at 1121. That court remanded the case to the trial court to determine whether the HGN evidence satisfied Frye. Id. The West Virginia Supreme Court in Barker reached virtually the same result, but also opined that estimates of BAC based on HGN test results were inadmissible, assuming the HGN test was found to be reliable. Barker, 366 S.E.2d at 646.
III. Reliability — Texas
(a) Theory
After consulting the literature concerning alcohol and its effects on human eye movement, and considering case law from other jurisdictions addressing the reliability of the HGN test, we conclude that the theory underlying the HGN test is sufficiently reliable pursuant to Texas Rule of Criminal Evidence 702. The scientific materials addressing the issue have reached the uniform conclusion that the consumption of alcohol has a cognizable effect on human eye movement. We believe that the accuracy of those sources cannot be reasonably questioned.
(b) Technique
We also conclude that the technique employed in the HGN test, as designed and promoted by NHTSA, is reliable pursuant to Rule 702. See Improved Sobriety Testing. In this jurisdiction, officers who administer the HGN test receive standardized training in its administration. When administering the HGN test, those officers must follow standardized procedures as outlined in the DWI Detection manual published by NHTSA. The test procedures, as outlined in the manual, require an officer to screen for factors other than alcohol that potentially contribute to, or cause, nystag-mus, such as other drugs, neurological disorders, and brain damage, prior to administering the HGN test.10 Therefore, we determine the technique employed in the HGN test to be a reliable indicator of intoxication. [769]*769We take judicial notice of the reliability of both the theory underlying the HGN test and its technique.
We are unable to conclude, however, that the HGN technique is a sufficiently reliable indicator of precise BAC. Given the results of NHTSA’s lab experiment, resulting in an average margin of error of .03%, and the dearth of other published writings on the accuracy of the NHTSA formula and technique, we cannot take judicial notice of the reliability of the HGN technique within the context of determining precise BAC based on the angle of onset of nystagmus.
(c) Application
Finally, we determine, pursuant to the third prong of the Kelly analysis, that the HGN technique was applied properly on the occasion in question. After examining the record in this case, we conclude that the HGN technique, as prescribed by the United States Department of Transportation and the State of Texas, was followed by Officer Trevino in his examination of appellant. Trevino’s testimony indicated that he followed the procedures as outlined in the DWI Detection manual.
IV. Proper Scope of HGN Testimony
We must determine the proper scope of testimony concerning the HGN test. In determining the proper scope of testimony concerning the HGN test, we consider the opinions of the highest courts of Arizona and Ohio on this issue. See State v. Superior Court, 149 Ariz. 269, 718 P.2d 171 (1986); State v. Bresson, 51 Ohio St.3d 123, 554 N.E.2d 1330 (1990). In each of those cases, the respective courts determined that, although testimony by a police officer concerning HGN test results was admissible as evidence that the defendant was under the influence of alcohol, a police officer would not be allowed to testify as to a defendant’s exact BAC based on the HGN results alone. Superior Court, 718 P.2d at 182; Bresson, 554 N.E.2d at 1336.
For testimony concerning a defendant’s performance on the HGN test to be admissible, it must be shown that the witness testifying is qualified as an expert on the HGN test, specifically concerning its administration and technique. In the case of a police officer or other law enforcement official, this requirement will be satisfied by proof that the officer has received practitioner certification by the State of Texas to administer the HGN. A witness qualified as an expert on the administration and technique of the HGN test may testify concerning a defendant’s performance on the HGN test, but may not correlate the defendant’s performance on the HGN test to a precise BAC, In the instant case, the record indicates that Officer Trevino did not attempt to quantify appellant’s exact BAC based on her performance on the HGN test.
A witness may not use the HGN evidence to quantify the defendant’s BAC. We have already concluded that we are unable to take judicial notice of the reliability of the formula and technique advocated by NHTSA to determine BAC based on angle of onset of nystagmus. NHTSA’s own study indicates a margin of error of .03% when its formula is used to determine BAC level based on the angle of onset. That margin of error is too high to allow estimations of a defendant’s BAC based on the angle of onset to be admissible. In addition, the State has other means available for quantifiable proof of a defendant’s BAC in a DWI prosecution which are much more effective and reliable, such as the blood test, breathalyzer, and urine test.
V. Application of Rule 403 Factors
We must next determine whether Officer Trevino’s testimony concerning the HGN test results, though reliable and relevant, was nevertheless inadmissible for some other reason. We must inquire whether Officer Trevino’s testimony concerning the HGN test results, though relevant, would have been unhelpful to the trier of fact. Nothing in the record indicates that a danger of unfair prejudice, confusion of the issues, misleading of the jury, undue delay, or presentation of cumulative evidence existed with respect to the HGN testimony at appellant’s trial. We conclude that the trial court’s decision to admit the testimony was proper. Therefore, we hold that the court of appeals [770]*770did not err in holding that Trevino’s testimony concerning appellant’s performance on the HGN test was admissible at her trial.
The judgment of the court of appeals is AFFIRMED.
MILLER, J., dissents.