GILBERTSON, Chief Justice

[¶ 1.] The Sixth Judicial Circuit Court granted class certification in this indirect-purchaser antitrust action to members of a certified class of South Dakota end-users (Class Members). This Court granted a discretionary appeal brought by Microsoft Corporation (Microsoft). We affirm the circuit court's certification order.

FACTS AND PROCEDURE

[¶ 2.] The Class Members, who are indirect purchasers of Microsoft Windows or MS-DOS operating systems software (OSS), are residents of the State of South Dakota. The Class Members allege that Microsoft has maintained a monopoly in the marketplace since the late 1980's or early 1990's. They contend that this monopoly was established through various anti-competitive acts such as stifling innovation in the market place and overcharging customers. The Class Members claim that Microsoft's actions "eliminated competition in the market for similar OSS, deprived purchasers of the benefits of a free market and injured consumers by forcing them to purchase Microsoft OSS at artificially high and supra-competitive prices in violation of South Dakota antitrust laws."

[¶ 3.] The Class Members sought and after extensive proceedings before the circuit court, obtained certification of a class in the Sixth Judicial Circuit. Microsoft was granted this discretionary appeal, raising the following issue for our review:

Whether the circuit court abused its discretion when it granted class certification in this indirect-purchaser antitrust action.

STANDARD OF REVIEW

[¶ 4.] "On review of an order denying or granting a motion to maintain a class, the lower court may be reversed only for an abuse of discretion." Trapp v. Madera Pacific, Inc., 390 N.W.2d 558, 560-61 (S.D. 1986); see also Swanson v. Sioux Valley Empire Elec. Ass'n Inc., 535 N.W.2d 755, 759 n2 (S.D. 1995).

[¶ 5.] "`An abuse of discretion refers to a discretion exercised to an end or purpose not justified by, and clearly against reason and evidence.'" Black v. Class, 1997 SD 22, ¶ 27, 560 N.W.2d 544. In applying the abuse of discretion standard, "`we do not determine whether we would have made a like decision, only whether a judicial mind, considering the law and the facts, could have reached a similar decision.'" State v. Wilkins, 536 N.W.2d 97, 99 (S.D. 1995) (citations omitted). Under such a standard of review "we must be careful not to substitute our reasoning for that of the trial court." State v. Larson, 512 N.W.2d 732, 736 (S.D. 1994).

ANALYSIS AND DECISION

[¶ 6.] The United States Supreme Court in Illinois Brick Co. v. Illinois, 431 U.S. 720, 729, 97 S.Ct. 2061, 2066, 52 L.Ed.2d 707 (1977), held that indirect purchaser suits for overcharge damages are barred under federal antitrust law. However, South Dakota, like many other states, has enacted a repealer statute that allows for indirect purchaser lawsuits to be maintained at the state level. Our state's repealer statute, SDCL 37-1-33, provides:

No provision of this chapter may deny any person who is injured directly or indirectly in his business or property by a violation of this chapter the right to sue for and obtain any relief afforded under § 37-1-14.3. In any subsequent action arising from the same conduct, the court may take any steps necessary to avoid duplicative recovery against a defendant.

(emphasis added).

[¶ 7.] In order to obtain certification of a class, the plaintiffs must satisfy all the requirements of SDCL 15-6-23 (FRCP 23(a)) (hereinafter Rule 23(a)) and at least one of the provisions of SDCL 15-6-23(b) (FRCP 23(b)) (hereinafter Rule 23(b)). Trapp, 390 N.W.2d at 560; Shangreaux v. Westby, 281 N.W.2d 590, 592-93 (S.D. 1979). Microsoft does not dispute that the requirements of Rule 23(a) are met on this appeal; therefore, we will only address the requirements of Rule 23(b). In its entirety, this statute reads:

An action may be maintained as a class action if the prerequisites of § 15-6-23(a) are satisfied, and in addition: (1) the prosecution of separate actions by or against individual members of the class would create a risk of

(A) inconsistent or varying adjudications with respect to individual members of the class which would establish incompatible standards of conduct for the party opposing the class, or

(B) adjudications with respect to individual members of the class which would as a practical matter be dispositive of the interests of the other members not parties to the adjudications or substantially impair or impede their ability to protect their interests; or

(2) the party opposing the class has acted or refused to act on grounds generally applicable to the class, thereby making appropriate permanent injunctive relief or corresponding declaratory relief with respect to the class as a whole; or

(3) the court finds that the questions of law or fact common to the members of the class predominate over any questions affecting only individual members, and that a class action is superior to other available methods for the fair and efficient adjudication of the controversy. The matters pertinent to the findings include:

(A) the interest of members of the class in individually controlling the prosecution or defense of separate actions;

(B) the extent and nature of any litigation concerning the controversy already commenced by or against members of the class;

(C) the desirability or undesirability of concentrating the litigation of the claims in the particular forum;

(D) the difficulties likely to be encountered in the management of a class action.

[¶ 8.] Plaintiffs assert that questions of law or fact common to all members of the proposed class predominate, including:

a. Whether Microsoft is a monopolist in the market for operating system software;

b. Whether Microsoft engaged in anti-competitive conduct in order to unlawfully maintain its monopoly powers;

c. Whether Microsoft's conduct violated South Dakota's antitrust laws;

d. The impact of Microsoft's activity in the relevant marketplace;

e. Whether Microsoft's conduct caused harm; and

f. Whether Plaintiffs and putative class are entitled to damages and appropriate measure of such damages.

According to General Tel. Co. v. Falcon, 457 U.S. 147, 161, 102 S.Ct. 2364, 2372, 72 L.Ed.2d 740 (1982), a court is required to conduct a rigorous analysis to determine if the elements of Rule 23 have been met. Furthermore, in applying the federal version of Rule 23, the United States Supreme Court has held that a party seeking certification must show "actual, not presumed," conformance with class certification requirements. Id. However, any doubts as to whether the class should be granted certification should be resolved in favor of certification. Bellinder v. Microsoft Corp., No. 99-CV-17089, 2001 WL 1397995, at *8 (KanDistCt Sep 7, 2001) (citing Arch v. American Tobacco Co., 175 FRD 469, 476 (EDPa 1997).

[¶ 9.] The question we are faced with here is whether this case is suitable for resolution on a class-wide basis. We stated in Trapp, 390 N.W.2d at 560:

Class actions serve an important function in our judicial system. By establishing a technique whereby the claims of many individuals can be resolved at the same time, the class suit both eliminates the possibility of repetitious litigation and provides small claimants with a method of obtaining redress for claims which would otherwise be too small to warrant individual litigation.

[¶ 10.] This is consistent with the last sentence of SDCL 37-1-33 which directs a trial court: "[i]n any subsequent action arising from the same conduct, the court may take any steps necessary to avoid duplicative recovery against a defendant." One method of insuring against this threat is to try all claims in a single proceeding.

[¶ 11.] We are aware that denial of class certification may be the death knell of claims due to the de minimus amounts of each individual claim which may economically preclude attempted redress by plaintiffs in separate law suits. c .f. Lick v. Dahl, 285 N.W.2d 594 (S.D. 1979). Herein the circuit court held that there were "a very large number of claimants with relatively small amounts at stake. Most consumers have little incentive to file suit independently because the high cost of litigation would far exceed their potential recovery." At oral argument before this Court, Microsoft conceded that should the class not be certified, individual consumers could not in all likelihood, economically pursue separate legal actions against it.

[¶ 12.] Moreover, the Plaintiffs are not required to prove their case on the merits at the class certification stage. Eisen v. Carlisle Jacquelin, 417 U.S. 156, 177-78, 94 S.Ct. 2140, 2152-53, 40 L.Ed.2d 732 (1974); Bellinder, 2001 WL 1397995, at *7. They must make a "threshold showing" that the antitrust activity, if proven, had a common impact on the class members. Bellinder, 2001 WL 1397995, at *7; In re Catfish Antitrust Litig., 826 F. Supp. 1019, 1041-42 (N.D. Miss 1993). The Plaintiffs must advance a method for determining generalized damages on a class-wide basis. Bellinder, 2001 WL 1397995, at *7; Catfish, 826 F. Supp. at 1042-43.

[¶ 13.] Microsoft first argues that the trial court abused its discretion because it evaluated Plaintiff's showing under Rule 23(b) under an improper relaxed standard of proof. In so doing, Microsoft seeks to avoid the effect of this deferential standard of review by arguing the circuit court committed an error of law in its improper application of a lower standard of proof. It relies upon our holding in State v. Vento, 1999 SD 158 ¶ 5, 604 N.W.2d 468, 469 that "by definition, a decision based on an error of law is an abuse of discretion." Microsoft argues that the circuit court improperly applied a standard of proof of "not so insubstantial or illusory as to amount to no method at all." We agree with Microsoft that such a standard is little better than no standard. It would invite procedural abuses of the legal system never intended for proper use of class actions. While the circuit court did acknowledge that such a standard has been applied by other courts, it did not rest its decision on that standard. Instead it plainly stated in its findings of fact and conclusions of law:

In applying the federal version of Rule 23, the United States Supreme Court has held that a party seeking certification must show "actual, not presumed," conformance with class certification requirements, and that a reviewing court must conduct a "rigorous analysis" in determining whether the elements of Rule 23 have been met. See General Telephone Company v. Falcon, 457 U.S. [at 160-61,102 S.Ct. at 2372, 72 L.Ed.2d 740]; . . . This Court has applied that standard.

(emphasis added).

[¶ 14.] Having determined the circuit court identified the proper legal standard, we now proceed to Microsoft's second contention that circuit court abused its discretion by improperly applying that standard when the court considered the evidence submitted to it on the certification question. Microsoft asserts that under Rule 23(b)(3), the Plaintiffs must demonstrate at the time class certification is sought that the "impact" on each class member can be established by common proof. Rule 23(b)(3) requires that either common questions of law or fact predominate. The circuit court found that "Plaintiffs need not calculate each class member's damages individually. Instead damages can be calculated in the aggregate for the class. A summing of all individual claims is not required." For support, the circuit court points to Coordination Proceedings Special Title (Rule 1550(b)) Microsoft I-V Cases, NO.JCCP. NO. 4106 (CalSuperCt, San Francisco Co., Aug. 29, 2000) and Catfish, 826 F. Supp. at 1043.

[¶ 15.] Microsoft specifically challenges the proposed methodology Plaintiffs advance to determine damages. Recently in McKie v. Huntley, 2000 SD 160, ¶ 20, 620 N.W.2d 599, 604, we set forth the general doctrine of proof of damages by a plaintiff, especially when the claimed difficulty in its determination was purportedly caused by the acts of the defendant who now is complaining about the lack of accuracy of such proof:

Difficulty in computing damages ought not to be confused with the requirement of proving damages as an essential element for recovery. Once the existence of damage has been shown by a preponderance of the evidence, a claimant must produce only the best evidence available to allow a jury a reasonable basis for calculating the loss. While jurors cannot speculate, they have some leeway in figuring damages. "Any doubt persisting on the certainty of damages should be resolved against the contract breaker." "[B]reaching parties may not complain when the task is made difficult by their own acts." All we require, therefore, is a reasonable basis for measuring the loss.

Id. (internal citations omitted). From a review of the record which is more fully discussed hereinafter, along with the detailed 86 findings of fact and conclusions of law entered by the circuit court, we are satisfied the circuit court accomplished what it set for itself as an appropriate standard, conducting a "rigorous analysis" of the entire certification question.

[¶ 16.] The term "threshold showing" based upon a "rigorous analysis" is probably not subject to a more specific legal definition than its generic understanding because of the various types of potential evidence that could be submitted to the court in the certification controversy. We are mindful that if the standard is set too low, it invites non-meritorious claims to be filed as class actions, which may force a potential defendant to evaluate the case more on economic costs of defending a class action rather than the case on the merits. On the other hand, should too high a standard be set, potential plaintiffs with valid claims, but limited means, are economically precluded from redress to the courts because they cannot each financially maintain individual actions. See Lick, 285 N.W.2d 594. SDCL 15-6-1 is a guide to 15-6-23 certification questions. It states in part that our civil procedure code is to "be construed to secure the just, speedy and inexpensive determination of every action."

[¶ 17.] In the case now before us, the evidence appears to be limited to a battle of experts. In such instances, the circuit court may be assisted by borrowing concepts from the standard which this Court routinely uses for determining the admissibility of purported expert evidence; that being the standard set forth in Daubert v. Merrell Dow Pharmaceuticals Inc., 509 U.S. 579, 113 S.Ct. 2786, 125 L.Ed.2d 469 (1993). This is not to suggest that the certification issue be combined with a full blown Daubert hearing, but rather has been described as a "lower Daubert standard." Howe v. Microsoft Corp, 2003 ND 12 ¶ 26, ___ N.W.2d ___ (citing Thomas Thomas Rodmakers, Inc. v. Newport Adhesives and Composites, Inc., 209 FRD 159, 162-3 (C.D. Cal 2002)). Under Daubert, the circuit court's rigorous certification analysis may be guided by whether "an expert's testimony rests on both `a reliable foundation and is relevant to the task at hand.'" Rogen v. Monson, 2000 SD 51, ¶ 13, 609 N.W.2d 456, 459 (citing State v. Hofer, 512 N.W.2d 482, 484 (S.D. 1994)).

In Daubert . . . the United States Supreme Court held that before expert scientific testimony may be received, it must be shown that: (1) it has been tested; (2) it has been subjected to peer review and publication; (3) the known or potential rate of error must be known; and (4) to what extent it has received general acceptance. The Daubert Court explained:

The adjective "scientific" implies a grounding in the methods and procedures of science. Similarly, the word "knowledge" connotes more than subjective belief or unsupported speculation. The term "applies to any body of known facts or to any body of ideas inferred from such facts or accepted as truths on good grounds." Webster's Third New International Dictionary 1252 (1986). Of course, it would be unreasonable to conclude that the subject of scientific testimony must be "known" to a certainty; arguably, there are no certainties in science.

Kuper v. Lincoln-Union Elec, 1996 SD 145, ¶ 39, 557 N.W.2d 748, 759-60 (citing Daubert, 509 U.S. at 590, 113 S.Ct. at 2795, 125 L.Ed.2d at 481). Admission of expert witnesses is also governed by an abuse of discretion standard. State v. Guthrie, 2001 SD 61, 30, 627 N.W.2d 401, 414-15.

[¶ 18.] The Class Members allege that they were harmed because Microsoft's antitrust violations forced direct purchasers to pay non- competitive prices for Microsoft OSS, and that a portion of the overcharged amount was passed on to them as indirect purchasers. As proof of the impact, Plaintiffs intend to use common evidence and economic methodologies.

[¶ 19.] In seeking certification as a class, the Class Members presented an affidavit by Dr. Leffler, an Associate Professor of Economics at the University of Washington. He presented three theories in which to show that Microsoft harmed the class by monopolistic conduct. Dr. Leffler opined in his affidavit that "the monopolization activity and overcharges at issue here substantially predate the class period. As a consequence, any Microsoft overcharge would have been embedded in the prices at all levels of distribution at the beginning of the class period." The Class Members argue, therefore, that Dr. Leffler's testimony "plainly establishes that the fact of injury can be shown with some certainty."

[¶ 20.] Moreover, the Class Members assert that the amount of antitrust injury can be calculated using "standard, yardstick methodologies." Dr. Leffler proposes that this can be determined by measuring the difference between the price a South Dakota end-user paid for Microsoft's OSS and the price the user would have paid in the absence of Microsoft's alleged illegal conduct. Three methods are offered.

[¶ 21.] The first method is the "comparative margin method." This method compares the prices of Microsoft OSS with the prices of products from a comparable market not affected by anticompetitive activity. The second method is termed the "competitive margin method" in which the margins earned by sellers in a comparable market free from antitrust violations are compared to the margins earned by sellers in the anticompetitive market. The third method is the "violation-free-period method." This method compares the price of Microsoft's OSS being charged during the anticompetitive time period with the price of OSS being charged during the period free of anticompetitive conduct.

[¶ 22.] In addition to Dr. Leffler's expert testimony, the Class Members submitted several published works from other economists. These works were based on the economists' empirical studies and analyses showing how Microsoft's alleged illegal activities have affected consumers.

[¶ 23.] In order to be granted class certification, the Class Members must also show that damages can be calculated on a class-wide basis. Bellinder, 2001 WL 1397995, at *7. Again, the Class Members use the testimony of Dr. Leffler. He opines that "the amount of Microsoft's overcharge can be estimated using a class-wide statistical determination of the relationship between costs faced by Microsoft's customers and the prices paid by end-users." Dr. Leffler proposes to calculate this amount by statistical estimation, using data available from public sources and third-party discovery.

[¶ 24.] As the circuit court correctly concluded, this judicial inquiry does not involve a determination as to the likely success of the Class Members' proposed methods. However, the Class Members must present at least one viable method for computing damages on a class-wide basis, one which a reasonable factfinder could accept. Microsoft I-V Cases, slip op. at 17-18; Gordon v. Microsoft Corp., 2001 WL 366432, at **11-12 (MinnDistCt Mar 30, 2001).

[¶ 25.] Microsoft puts forth numerous arguments refuting Dr. Leffler's opinions. For example, one such expert, Dr. Hausman, submitted affidavits and provided testimony for Microsoft. The essence of Microsoft's argument is that there are a multitude of complexities and variances in the marketplace and distribution chain that will affect the Class Members' ability to analyze whether, and the extent to which, overcharges were passed on to consumers. Additionally, Microsoft claims that the Class Members have failed to make a "threshold showing" of impact because of problems relating to the nature and extent of the overcharges being passed- on to consumers.

[¶ 26.] We find that the circuit court did not abuse its discretion when it did not completely accept Microsoft's arguments at this stage of the proceedings. The disagreement on impact and damages should be adjudicated at trial by the factfinder, not by a court on a motion for class certification. Avoiding a "battle of the experts" at the class certification stage is consistent with Supreme Court authority. See Eisen, 417 U.S. at 178, 94 S.Ct. at 2153 (concluding that on a motion for class certification, the determination is whether the Plaintiffs have satisfied the requirements of Rule 23, not whether they will prevail on the merits). The court in Microsoft I-V Cases stated:

The question at this stage is not whether plaintiffs will be able to carry their burden of proving that their experts' analyses are reliable, but whether it appears that the differences between the experts can be intelligently presented and evaluated within the framework of the class action. On a motion for class certification, it is inappropriate to resolve a battle of the experts. Whether or not [plaintiffs' experts] is correct in his assessment of common/impact injury is for the trier of fact to decide at the proper time.

Slip op. at 15. (internal quotations and citations omitted).

[¶ 27.] At oral argument, Microsoft relied heavily upon the recent case of A M Supply v. Microsoft Corp, 252 MichApp 580, 654 N.W.2d 572 (Mich. 2002). Therein the Court reversed a previous class certification by a trial court. We do not find A M persuasive. Initially, Michigan applies a "clear error" standard of appellate review while South Dakota uses the "abuse of discretion" standard that grants a trial court more appellate deference. A M, 252 MichApp at 588, 654 N.W.2d at 577. An abuse of discretion occurs only where "a judicial mind, in view of the law and circumstances, could [not] have reasonably reached the same conclusion." State v. Barber, 1996 SD 96, ¶ 14, 552 N.W.2d 817, 820 (citations omitted). "`Abuse of discretion is the most deferential standard of review available with the exception of no review at all.'" Guthrie, 2001 SD 61, ¶ 89, 627 N.W.2d at 431 (Gilbertson, J., concurring in result) (citing State v. Chamley, 1997 SD 107 ¶ 51, 568 N.W.2d 606, 620 (Gilbertson, J., dissenting) (citing Martha S. Davis, Basic Guide to Standards of Judicial Review, 33 S.D. Law Rev, 468, 480 (1988)).

[¶ 28.] The A M Court proceeded to review what it determined to be the "battle of the experts." It was once again Dr. Leffler for the plaintiffs and Dr. Hausman for Microsoft. The A M court reversed certification after a very extensive examination of each expert's methodology. A M Supply, 252 MichApp at 584, 654 N.W.2d at 575. It concluded Leffler's theories insufficient to support certification, as they were "slogans, not methods of proof." A M Supply, 252 MichApp at 638-39, 654 N.W.2d at 602. Beyond the differing standards of appellate review between our two courts, it further appears from our analysis that under South Dakota case law, the A M court would have entered into an examination of the case on the evidentiary merits rather than the threshold issue of class certification. There appears to be little left to ultimately try in front of a jury after it settled the "Battle of the Experts" at the certification stage.

[¶ 29.] In South Dakota the admissibility question awaits a Daubert hearing. Thereafter, other procedural devices such as a motion for summary judgment may be invoked. Assuming the "Battle of the Experts" raises questions of fact which are not settled by these pre-trial proceedings, such matters are best left for a jury determination with the experts subject to cross-examination in front of a jury rather than reliance upon numerous salvos of pre-trial affidavits by opposing experts in a certification hearing.

When opposing experts give contradictory opinions on the reliability or validity of a conclusion, the issue of reliability becomes a question for the jury. See State v. Hofer, 512 N.W.2d 482, 484 (S.D. 1994). The trial process is well equipped to deal with contradictory opinions. "Vigorous cross-examination, presentation of contrary evidence, and careful instruction on the burden of proof are the traditional and appropriate means of attacking shaky but admissible evidence." Daubert 509 U.S. at 596, 113 S.Ct. at 2798, 125 L.Ed.2d at 484 (citations omitted).

Guthrie, 2001 SD 61, ¶ 38, 627 N.W.2d at 417.

[¶ 30.] Microsoft cites us to authority from other jurisdictions, which it interprets to conclude that a mere clash between "experts" is not enough by itself to support class certification. That is correct to a point. Production of a self-professed expert is simply not enough to meet the certification requirements under our rigorous analysis standard. However, this Court has consistently refused to extend any gate-keeping function to usurp the factual determination role of the ultimate trier of fact.

We begin analysis of this issue from the long-accepted premise that the purpose of expert testimony is to assist the jury as the trier of fact and not to supplant it. This state is not a trial-by-expert jurisdiction. The value of the opinion of an expert witness is no better than the facts upon which it is based. It cannot rise above its foundation and proves nothing if its factual basis is not true. It may prove little if only partially true. The credibility of witnesses and the evidentiary value of their testimony falls solely within the province of the jury.

Lien v. Class, 1998 SD 7, ¶ 23 n12, 574 N.W.2d 601, 610 (citing Bridge v. Karl's Inc, 538 N.W.2d 521, 525 (S.D. 1995)).

[¶ 31.] Our decision here is in line with other jurisdictions that have faced the same certification issue. Every state, with the exception of Maine and Michigan, that has a repealer statute has granted class certification to indirect purchasers seeking redress against Microsoft for antitrust violations. The very same pass-through and overcharge arguments that Microsoft makes here, have been rejected by a large majority of courts considering the issue. In re New Mexico Indirect Purchaser Microsoft Corp. Antitrust Litig., NO. D-0101-CV-2000-1697 (NMDistCt., Santa Fe Co., Sept. 30, 2002); In re Florida Antitrust Litig., No. 99-27340 CA 11 (FlaCirCt, Dade Co., Aug. 26, 2002); Howe, 2003 ND 12; Bellinder, 2001 WL 1397995; Capp v. Microsoft Corp., No. 00-CV-0637 (Wis CirCt, Dane Co., June 28, 2001); Friedman v. Microsoft Corp., CV-2000-000722 (Consol.) (ArizSuperCt, Maricopa Co., Nov. 15, 2000 July 13, 2001; Gordon v. Microsoft Corp., No. 00-5994, 2001 WL 366432 (MinnDistCt, Mar. 30, 2001), aff'd, 645 N.W.2d 393 (Minn 2002); Microsoft I-V Cases, supra.

[¶ 32.] For the foregoing reasons, we find that the trial court did not abuse its discretion in granting class certification to the Class Members. We find that the Class Members have met their "threshold showing" of harm to end-users/consumers. Its decision in certifying this case as a class action is sufficiently supported by the evidence and applicable law and satisfies all of the requirements of Rule 23.

[¶ 33.] We remand to the circuit court for further proceedings consistent with this opinion.

[¶ 34.] MEIERHENRY, Justice, and TUCKER, Circuit Judge, concur.

[¶ 35.] KONENKAMP, Justice, and AMUNDSON, Retired Justice, concurs with a writing.

[¶ 36.] MEIERHENRY, Justice, not having been a member of the Court at the time this action was submitted to the Court, was appointed as a Circuit Judge to sit for SABERS, Justice, disqualified.

[¶ 37.] TUCKER, Circuit Judge, sitting for ZINTER, Justice, disqualified.