The court granted this interlocutory appeal by an order appearing at 512 F.2d 719 to consider the important question of the applicability of the doctrine of res judicata to this school desegregation litigation. In Deal v. Cincinnati Board of Education (Deal I), 244 F.Supp. 572, 582 (S.D.Ohio 1965), the district court denied relief upon a finding that the “plaintiffs have failed to establish a deprivation of rights under the law or under the Constitution of the United States . . .” It had been stipulated that the Cincinnati school system included a number of schools attended almost entirely by Negro pupils, a number attended entirely by white pupils and a number attended by both Negro and white pupils in various percentages. The district court found the Cincinnati school system had been operated on the “neighborhood plan” and that “the racial composition of each school is simply a result of the racial composition of the neighborhoods which they serve.” Id. at 580.
Deal I was affirmed on appeal to this court, 369 F.2d 55 (1966), and certiorari was denied by the Supreme Court, 389 U.S. 847, 88 S.Ct. 39, 19 L.Ed.2d 114 (1967). We held that where the sole limitation imposed by state action on the choice of schools by pupils results from adherence to the neighborhood school concept this limitation does not share “the arbitrary, invidious characteristics of a racially restrictive system.” 369 F.2d at 60. This court declared that the critical fact determination in an action charging a school board with violation of the rights of minority pupils is whether an existing racial imbalance is intentionally caused by discriminatory practices of the board. A statistical imbalance *346standing alone is not enough; official discrimination is required to invoke the protection of the Fourteenth Amendment. On this basis we upheld the exclusion by the district court of evidence of alleged discrimination in the public and private housing markets of Cincinnati — acts over which the school board had no control.
Though the judgment of the district court in Deal I was affirmed on the finding that the racial imbalance which existed in the Cincinnati school system as a whole was not intentionally caused by the Board, the case was remanded for further findings with respect to claimed discrimination in specific schools and programs, and alleged harmful effects of the racial imbalance that did exist. New findings were made by the district court following remand, and the case was brought to this court once again. In affirming Deal II, Deal v. Board of Education, 419 F.2d 1387 (1969), cert. denied, 402 U.S. 962, 91 S.Ct. 1630, 29 L.Ed.2d 128 (1971), we upheld the findings that there was a high correlation between the distribution of Negro pupils throughout the school system and the general neighborhood residential patterns of the City; that there were topographical and man-made barriers which required irregular boundary lines for various attendance districts; and, specifically, that there was no evidence of racial discrimination by the Cincinnati Board in locating schools, assigning teachers and staff or in failing to furnish equal facilities to different schools.
The “subsidiary findings” with respect to particular schools and programs were also upheld. The district court and this court disagreed with the contentions of the plaintiffs-appellants in Deal II that the law had been changed since Deal I by the Supreme Court decisions in Green v. County School Board of New Kent County, 391 U.S. 430, 88 S.Ct. 1689, 20 L.Ed.2d 716 (1968); Raney v. Board of Education of the Gould School District, 391 U.S. 443, 88 S.Ct. 1697, 20 L.Ed.2d 727 (1968); and Monroe v. Board of Commissioners of the City of Jackson, 391 U.S. 450, 88 S.Ct. 1700, 20 L.Ed.2d 733 (1968). These three cases were viewed as holding that a court may require a school board to discard as inadequate a plan based on “freedom of choice” or “free transfer” which has not effectively desegregated a dual school system, and thus as applying only to districts formerly having de jure segregation. 419 F.2d at 1396.
The Deal case was brought as a class action on behalf of ninety-six named “minor citizens of the State of Ohio” and on behalf of “thousands of [other] Negro minors within the school district of Cincinnati, who are similarly situated because of race and color.” The present case was instituted as a class action by “parents of minor children thereof, attending schools in the public school system of the State of Ohio and in the City of Cincinnati.” The action was brought by each plaintiff on behalf of himself and his minor children “and on behalf of all persons in the State of Ohio similarly situated.” Y The complaint charges the defendants with engaging in numerous discriminatory acts, practices, policies and customs and seeks declaratory and injunctive reliefJs ^Each of the defendants in this action pled, inter alia, that the doctrine of res judicata bars relitigation in this case of the issues adjudicated in Deal I and II.J, In a “Motion to Determine the Affirmative Defense” the plaintiffs requested the district court “to resolve the issue‘raised by the affirmative defense of res judicata ” which had been pled by the defendants.
The district court filed an opinion in response to this motion holding that “defendants may properly assert the affirmative defense of res judicata in the present case, or, more precisely, that they may assert here the collateral estoppel aspect of that general doctrine.” The accompanying order contained a certification under 28 U.S.C. § 1292(b) for immediate appeal, which this court granted.
The district court considered the question of whether intervening changes had occurred in the law applicable to school *347desegregation litigation since Deal I and II which would make it inappropriate to permit the defendants to rely on res judicata or. collateral estoppel. The court concluded that the basic holdings of Deal I and II have not been reversed or overruled. It was noted that instances where school boards had been charged with the affirmative duty to weed out all vestiges of segregation “root and branch” involved remedy proceedings where previous actions or proceedings had established constitutional violations. The district court held that the Supreme Court decisions impose no such affirmative duty in the absence of a finding that a board has operated a dual school system or that de jure segregation has been practiced.
While finding that changes in the law since Deal I and II have not been so drastic as to permit a relitigation of the issues decided in those cases, the district court did note “developments and refinements” in the law since Deal. One such development or refinement was stated by the district court as follows:
And, even where there has been no showing of duality or prior deliberate discrimination, a school board should certainly consider reasonable ways to alleviate racial imbalance and a failure to act in this regard could be part of the cumulative evidence of a possible constitutional violation in certain circumstances.
In its opinion the district court held that the question of segregative intent was critical to the decisions in Deal I and II and that this issue was settled by a finding that the Cincinnati Board had no such intent up to July 26, 1965, when the Deal inquiry ended. Thus, the court held that the inquiry in the present case is limited to the existence of segregative intent in the period since July 26, 1965. Tríe court found that the class of plaintiffs in the present case is substantially the same as in Deal. \ Noting that an application of strict res judicata principles would bar any further litigation between the parties, the court concluded that the less comprehensive doctrine of collateral estoppel should properly be applied and held that the parties to the present action are foreclosed from “the relitigation of essential facts or issues which were previously litigated by the parties (or their privies) and judicially determined.”
' The district court was clearly correct in finding that Deal I and II continue to have “vitality.” See Higgins v. Grand Rapids Board of Education, 508 F.2d 779 (6th Cir. 1974). In fact, the plaintiffs in the present case agree in their brief that the “holding [of Dea/] that racial imbalance alone does not justify a school desegregation order by a Federal District Court . . . remains good law . .” (Supp. Brief for Appellants at 21.) However, they maintain that certain aspects of Deal have been “overtaken” by more recent decisions of the Supreme Court and this court. Plaintiffs maintain that to the extent the Deal finding of no segregative intent was based on a “dominant purpose” test rather than one which looked to the natural and probable effects of the Board’s actions and inactions the finding is no longer valid. In this respect plaintiffs rely, inter alia, on this court’s opinions in Oliver v. Michigan State Board of Education, 6 Cir., 508 F.2d 178 (1974), cert. denied 421 U.S. 963, 95 S.Ct. 1950, 44 L.Ed.2d 449 (1975); Berry v. Benton Harbor School District, 6 Cir., 505 F.2d 238 (1975); Brinkman v. Dayton Board of Education, 6 Cir., 503 F.2d 684 (1974); Bradley v. Milliken, 6 Cir., 484 F.2d 215 (en banc 1973), rev’d on other grounds sub nom. Milliken v. Bradley, 418 U.S. 717, 94 S.Ct. 3112, 41 L.Ed. 1069 (1974); Davis v. School District of Pontiac, 6 Cir., 443 F.2d 573, cert. denied 404 U.S. 913, 92 S.Ct. 233, 30 L.Ed.2d 186 (1971); and Supreme Court decisions, particularly Swann v. Charlotte-Mecklenburg Board of Education, 402 U.S. 1, 91 S.Ct. 1267, 28 L.Ed.2d 554 (1971); and Keyes v. School District No. 1, 413 U.S. 189, 93 S.Ct. 2686, 37 L.Ed.2d 548 (1973).'\These intervening decisions are said to have changed the law sufficiently to render collateral estoppel inapplicable to the *348present case.^A The plaintiffs argue further that school cases are sui generis and involve national public policy of the highest priority which requires that res judicata and collateral estoppel at least be limited in their application.
In Wright v. Council of the City of Emporia, 407 U.S. 451, 92 S.Ct. 2196, 33 L.Ed.2d 51 (1972), the Supreme Court described as fruitless and irrelevant any inquiry into the “dominant” motivation of school authorities where the schools had previously been subject to state-enforced racial segregation. Instead, the Court said, it had “focused upon the effect — not the purpose or motivation — of a school board’s action in determining whether it is a permissible method of dismantling a dual system.” Id. at 462, 92 S.Ct. at 2203. (emphasis added). On the other hand, in Keyes v. School District, supra, which involved a school system like Cincinnati’s where there had never been state-mandated segregation, the plaintiffs were required to prove “not only that segregated schooling exists but also that it was brought about or maintained by intentional state action.” 413 U.S. at 198, 93 S.Ct. at 2692. In Keyes, the Court emphasized that the “differentiating factor between de jure segregation and so-called de facto segregation ... is purpose or intent to segregate.” 413 U.S. at 208, 93 S.Ct. at 2697. (emphasis in original). Thus, contrary to plaintiff’s claim, the Supreme Court appears to have held that intent is synonymous with purpose in determining whether a racial imbalance which is found to exist in a school system that was never segregated by state law results in a constitutional violation. In a school system which was previously segregated by state law there is no requirement that intent be shown. The state action requirement of the Fourteenth Amendment is not an issue. On the other hand, in a school system which has never been operated under a state requirement of separation of the races, de facto segregation may only be treated as resulting from state action in violation of the Fourteenth Amendment if it is shown to result from intentional acts, omissions or policies of public officials or public bodies. Thus, the de jure/de facto distinction has been retained (see concurring and dissenting opinion of Mr. Justice Powell in Keyes, 413 U.S. at 217, 93 S.Ct. 2686), and the Supreme Court continues to apply different standards to the determination of two different questions: (1) Are the methods adopted by a board effective to dismantle a dual system? and (2) Does a racial imbalance in a unitary system exist because of actions and policies of public officials, primarily the school board, which reflect and carry out a purpose or intent to segregate? In this case we are concerned only with the second question.
The district court expressed some difficulty in reconciling the decisions of this court since Deal. However, Judge Porter concluded that references to the “effect test” in our opinions relate to the fact that a court may infer intent, which is a subjective fact not easily proven, from evidence of racial imbalance accompanied by acts or omissions of a school board, the natural and probable result of which is to produce or perpetuate a segregated school system. See, e. g., Berry v. Benton Harbor School District, supra; Oliver v. Michigan State Board of Education, supra. This is a correct reading of our decisions. In these cases and in Bradley v. Milliken, supra, the court did not dispense with the requirement that segregative intent or purpose be proven, but rather held that this element of the cases had been proven by showing acts and policies of the school authorities which had the natural and foreseeable effect of producing segregated schools, a showing from which the required intent could be inferred. In Higgins, which was decided in the light of the Supreme Court’s treatment of the requirement of intent in Keyes, we noted that it is permissible for a court to infer intent from proven circumstances. 508 F.2d at 793.
We conclude that there has been no such change in the law since Deal as to prevent altogether the appli*349cation of the doctrine of collateral estoppel to this case. Though there is a strong public policy against the continuance of racial segregation in public schools we do not believe that school desegregation cases are so different from other types of litigation that principles of res judicata and collateral estoppel should never be applied to them. The public policy consideration that there be an end to all litigation which underlies the doctrines of res judicata and collaterrgl estoppel is itself firmly established. This court has held, however, that “[n]either collateral estoppel nor res judicata is rigidly applied. Both rules are qualified or rejected when their application would contravene an overriding public policy or result in manifest injustice. Tipler v. E. I. duPont deNemours and Co., 6 Cir., 443 F.2d 125, 128 (1971).
This appeal requires that we determine the extent to which the doctrine of res judicata should be applied in order to accommodate two competing public policies and avoid manifest injustice. We believe that the district court properly limited the application of the doctrine to this ease by holding that the principles of collateral estoppel, as opposed to res judicata, will be observed. Deal was filed as a “spurious class action” under Rule 23 of the Federal Rules of Civil Procedure prior to the 1966 amendment thereof. According to the authorities, an adverse judgment in such an action was not binding on persons who were not parties to the class action. See 3B J. Moore, Federal Practice 123.-10-1, at 23-2769; f 23.11[3], at 23-2851. On the other hand a public body should not be required to defend repeatedly against the same charge of improper conduct if it has been vindicated in an action brought by a person or group who validly and fairly represent those whose rights are alleged to have been infringed. Though the plaintiffs in the instant action are not the same persons as those who instituted Deal, that action was brought to vindicate the rights of all minority school children and parents affected by the actions and policies of the Cincinnati Board. There is a strong community of interests between the Deal plaintiffs and the Bronson plaintiffs and both actions sought relief on behalf of the same large group of black citizens. For the purposes of collateral estoppel we do not consider the plaintiffs in the present action to be “strangers” to the Deal litigation. The proper balance between the public policy of requiring a finality to judgments which settle issues in litigation and that of preventing the denial of equal protection of the law to a generation which comes after such a judgment has been rendered may be achieved by applying the rule of “issue preclusion.” See Humphreys v. Tann, 487 F.2d 666 (6th Cir. 1973), cert. denied, 416 U.S. 956, 94 S.Ct. 1970 (1974); Davis v. McKinnon & Mooney, 266 F.2d 870 (6th Cir. 1959); Bernhard v. Bank of America, 19 Cal.2d 807, 122 P.2d 892 (1942).
The district court’s order forecloses the plaintiffs from showing that the defendants did, prior to July 26, 1965, act with a segregative intent or that the actions, inactions or policies of the Board prior to that date violated the constitutional rights of minority pupils or their parents. These issues have been decided and under the issue preclusion application of collateral estoppel may not be reopened. (Nevertheless, there are children attending the Cincinnati schools now who either were not born in 1965 or had not started to school. Their claims were not in existence at the time of the judgment in Deal and could not have been extinguished by ibj Lawlor v. National Screen Service Corp., 349 U.S. 322, 328, 75 S.Ct. 865, 99 L.Ed. 1122 (1955). The complaint of such children and their parents of alleged continuing wrongful acts subsequent to 1965 declares a different cause of action than that concluded by Deal, one to which estoppel does not apply. Cream Top Creamery v. Dean Milk Co., 6 Cir., 383 F.2d 358, 363 (1967); United States v. General Electric Co., 358 F.Supp. 731, 740 (S.D.N.Y.1973).
In order to establish their claim of a present denial of constitutional *350rights these plaintiffs must be permitted to show whether the post-1965 actions, inactions and policies of the defendants have caused or contributed to the conditions of which they complain. However, this evidence cannot be considered in a vacuum any more than the actions and decisions of the defendants have taken place in a vacuum. In oral argument before this court counsel for the defendant Cincinnati Board stated that the plaintiffs may introduce evidence of conditions prior to July 26, 1965 “for background purposes,” but that application of res judicata principles prevents the finding of violation prior to that date. We agree. pTo the extent that the pre-1965 actions and policies of the Board and the conditions which existed on July 26, 1965 are relevant to a determination of the existence or non-existence of unlawful segregation at the times involved in this case, the district court may take judicial notice of facts stipulated or proven in DeaL\^
In the per curiam opinion granting an appeal from the interlocutory order of the district court we stated:
The effect of this ruling appears to be that plaintiffs would be collaterally es-topped from relitigating any of the issues determined in the prior litigation between the plaintiffs in the earlier class action and the defendant board and from introducing evidence as to events occurring prior to July 26, 1965. 512 F.2d at 719 (emphasis added).
We would be unable to affirm the order of the district court if this were its effect. However, upon restudy of the order and memorandum opinion we conclude that it does not preclude the introduction of evidence concerning events which occurred prior to July 26, 1965.
At this stage of the proceedings, when there has been no opportunity to offer evidence, the district court has very properly made no attempt to catalogue or describe the evidence which will be admitted. If new evidence of pre-Deal occurrences or conditions is offered the district court will determine in each instance whether or not such evidence is relevant1 to the inquiry in the present case, i. e., does it shed light on the claim that minority pupils and their parents have been denied equal protection of the law by the defendants during the post-July 26, 1965 period involved in this action? As we have noted previously, in discussing developments and refinements since Deal, the district court referred to “the cumulative evidence of a possible constitutional violation.” Ultimate decision of the present case will necessarily require consideration of cumulative evidence. Adherence to the doctrine of issue preclusion in no way forecloses the consideration of such evidence.
The order of the district court as modified and interpreted herein is affirmed. Each party will bear its own costs on this appeal.
. Rule 401, Federal Rules of Evidence (1975), contains a definition of “Relevant Evidence” and the Advisory Committee’s Notes to Rule 401 deal with the definition.