The question presented is whether a worker who has obtained an award of workers’ compensation benefits that is pending on appeal to the Workers’ Compensation Appeal Board must seek to present to the wcab, during its review of the earlier award, evidence of a change in physical condition, which occurred after the award, that the worker claims supports a further and separate claim of benefits arising from the same injury in order to avoid the bar of res judicata and preserve his right to a hearing on the further and separate claim. We hold that he is not required to seek to present the evidence during the appeal.
The Workers’ Compensation Appeal Board found, in October, 1974, that Jessie Askew was injured on February 19, 1971, and affirmed a referee’s November, 1972, decision awarding her benefits for a closed period from February 20, 1971, to July 26, 1971.
Subsequently, in a separate proceeding, the wcab found1 that there had been a change in Askew’s physical condition which occurred after the November, 1972, hearing and award, but before the hearing and decision by the wcab on review of that award. The wcab found in that second proceeding that Askew was entitled to continuing benefits from a date in 1973,2 on the basis of testimony of medical experts who made a diagnosis in 1973 (i.e., before the wcab’s 1974 *718decision in the first proceeding) of problems arising from the 1971 injury that were not evident in 1972 when the hearing before the referee that resulted in the earlier award was held.3
An order of a referee can be and is dispositive4 unless an appeal is taken to the wcab. Here, Askew took an appeal in the first proceeding to the wcab. It was her claim, rejected in 1974 by the wcab in that proceeding, that the record made before the referee at the first hearing in November, 1972, supported an award of benefits beyond the five-month closed period for which they were awarded.
The wcab found in the second proceeding that there was evidence of a change in physical condition commencing in 1973. That evidence, accordingly, could not have been made part of the record at the time of the first hearing in November, 1972. Askew’s employer, the Ann Arbor Public Schools, contends that because the additional evidence was available in 1973 — while the referee’s 1972 decision was still pending on appeal to the wcab— Askew should have sought to present the additional evidence during the wcab review in the first proceeding before the 1974 wcab decision in that proceeding was made.
The workers’ compensation act provided that if a claim for review by the wcab' of a referee’s decision is filed, the wcab ”may hear the parties, *719together with such additional evidence as it in its discretion may allow them to submit . . . .”5
The Court of Appeals agreed with the Ann Arbor Public Schools that Askew should have sought to present the evidence that she was disabled from a date in 1973 to the wcab during its review in the first proceeding and held that Askew was precluded by the doctrine of res judicata from obtaining continuing benefits. The Court of Appeals observed that this Court in Gose v Monroe Auto Equip Co, 409 Mich 147, 160-161; 294 NW2d 165 (1980), had said in effect "that the doctrine of res judicata bars a claim which a plaintiff in a worker’s compensation case could have brought, but did not.”6
Ann Arbor Public Schools argues that when an appeal is taken from a referee’s decision to the wcab, the decision of the wcab and not the decision of the referee is the "award” within the meaning of this Court’s repetition in Gose of its earlier statement in Hlady v Wolverine Bolt Co, 393 Mich 368, 375-376; 224 NW2d 856 (1975), " 'that a compensation award is an adjudication as to the condition of the injured workman at the time it is entered, and conclusive of all matters adjudicable at that time.’ ”
In neither Gose nor Hlady, however, did this Court focus on the question now presented, whether the "time” of the award for res judicata purposes is the date of the decision by the referee or the date of the decision by the wcab where an intervening change in physical condition may, as recognized in the passage from Hlady quoted in *720Gose,7 justify a further award of benefits or the stopping of payment on an award previously entered.
This Court’s decisions in Gose and Hlady that the doctrine of res judicata bars claims actually litigated and also those arising out of the same transaction that could have been, but were not, brought does not address the question whether a worker who has obtained a referee’s award that is pending on appeal to the wcab must seek to present, during the wcab’s review of the earlier award, evidence in support of a further and separate claim for benefits on the basis of a change in physical condition that occurred after the referee’s award arising from the same injury to avoid the bar of res judicata and preserve his right to a hearing on the further and separate claim.
Neither general res judicata doctrine8 nor policy *721requires one result in preference to the other. Requiring a worker claiming further benefits or an employer claiming that payment of benefits should be stopped to seek to present to the wcab evidence of a change in physical condition that occurs during the pendency of an appeal thereto would not be unfair as long as sufficient time remained to do so before the wcab ruled and the request to present the evidence would not unduly delay the ultimate decision. In the instant case, however, the wcab indicated that the worker or employer is not required to seek to present such evidence on appeal.
The wcab declared in the instant case that, for purposes of the application of the doctrine of res judicata, the date of the first hearing and decision before the referee, November, 1972 — and not the date of the hearing before or the decision by the wcab — was determinative. The wcab said that the November, 1972, decision was res judicata "as to plaintiffs physical condition through the date of hearing.” (Emphasis in original.)* ******9 That declaration of the wcab may reflect an assessment of the *722frequency with which petitions to present additional evidence are granted by the wcab, the likelihood of delay if such petitions are routinely granted, or the systemic or substantive problems that might develop if the determinative date is the date of decision by the wcab (or the date of a hearing before the wcab or a date preceding the hearing).
It is clear from the language of the statute ("as it in its discretion may allow”)10 and well established that had Askew sought to introduce the additional evidence, the wcab would not have been obliged to hear it.* 11 Adoption of the rule advocated by Ann Arbor Public Schools would not, unless the wcab were to routinely grant petitions to submit additional evidence, result in the economies of a single adjudication visualized by the Ann Arbor Public Schools.
If we were to adopt the rule advocated by the Ann Arbor Public Schools, it would have operative effect only in cases where the wcab chose to grant a petition to submit additional evidence and in cases where no such petition was filed. In those cases where a petition was filed and the wcab declined to receive additional evidence, the worker would clearly be entitled to a hearing before a *723referee regarding a further and separate claim to benefits.
Adoption of a rule making the date of hearing or award by the wcab determinative might produce a mountain of additional "protective” petitions that would be routinely denied by the wcab and become a source of considerable litigation in those cases where a petition was not filed on the question whether a protective petition was required to be filed.
1985 PA 103 provides a new administrative procedure for adjudicating contested claims for workers’ compensation. Applications for hearing filed after March 31, 1986, are to be heard by a workers’ compensation magistrate rather than a referee. An appeal from the magistrate’s decision is to be taken to the newly established workers’ compensation appellate commission in lieu of the wcab. Act 103 provides for the phasing out of the functions of the referee and the wcab. The wcab reviews a decision of a referee de novo.12 The findings of fact of a magistrate are to be considered conclusive by the commission if supported by competent, material, and substantial evidence on the whole record.13
Under the new procedure established by Act 103, authorization for the taking of additional evidence on review to establish a change in physical condition has been eliminated. The appellate commission "may remand a matter to a worker’s compensation magistrate for purposes of supplying a complete record if it is determined that the record is insufficient for purposes of review.”14 The *724determinative date for res judicata purposes under the new procedure will be the hearing before the magistrate. The Legislature has thus enacted an administrative system for adjudicating contested claims for workers’ compensation that clearly does not contemplate the taking of additional evidence on appeal where there has been a change in physical condition. If we were to adopt the new rule advocated by the Ann Arbor Public Schools and reverse the decision of the wcab in the instant case, it would affect only those cases where a hearing was sought before April 1, 1986.
Although a referee’s decision is reviewable de novo by the wcab,15 it does not follow that the date of decision by the wcab is determinative for res judicata purposes. The wcab reviews the record made before the referee. The wcab decision is " 'conclusive of all matters adjudicable, [including the condition of the injured worker] at [the] time’ ”16 that record was made. The question here presented is whether the worker must, to prevent application of the doctrine of res judicata, seek to expand that record to include evidence of a change in physical condition that occurred after the referee’s hearing was concluded.
Adoption of a rule making the date of hearing or award by the wcab determinative could work against employers in other cases. If there has been a change in the physical condition of a worker receiving benefits pursuant to an order of a referee or the wcab, an employer may seek a stop-payment order. If we were to hold that an injured worker is required to seek to present evidence of a change in physical condition occurring between the referee’s award and the hearing before the wcab, then an employer might also be required to *725seek to present evidence of a change in condition justifying a stop-payment order17 where the employer was aware (or possibly should , have been aware) of the change in condition between the referee hearing and the wcab hearing.
Having in mind the difficulty confronting the wcab in disposing of the backlog of cases still subject to its jurisdiction, we decline to adopt a new rule that might further add to its burden and exacerbate the problem with which it is confronted by requiring injured workers and employers to file petitions seeking to present evidence of a change in physical condition, which occurs between the referee and the wcab hearings, to the wcab during its review to avoid a possible res judicata determination. Were we to adopt such a rule, the wcab could deny all such petitions. Then a decision of this Court adopting such a rule would have added more paperwork (in cases where a petition was filed and denied), created a trap for the unwary (in cases where a petition was not filed), and become a source of litigation for the magistrates, the appellate commission, and the wcab as well, who would be called upon in cases where a petition was not filed to assess whether, in particular cases, a petition to present such evidence should have been filed with the wcab.
We are not persuaded that the administration of justice would be advanced by adoption of a rule requiring the employee to present evidence of a change in physical condition, which occurred after the award, that the worker claims supports a further and separate claim of benefits, arising from the same injury in order to avoid the bar of res judicata and preserve his right to a hearing on the further and separate claim._
*726We emphasize that although both of Askew’s claims arose out of the same injury, Askew’s claim in the second proceeding was based on a change in physical condition that occurred after the hearing before the referee in the first proceeding had concluded which gave rise to a claim separate and distinct from her claim in the first proceeding.
We reverse the decision of the Court of Appeals and remand the cause to the wcab.
Brickley, Archer, and Griffin, JJ., concurred with Levin, J.On December 26, 1984. See n 2.
March 23, 1976. This award was based on a petition for benefits filed March 23, 1977. The one-year back rule, MCL 418.833; MSA 17.237(833), was applied, and that explains why benefits were awarded from March 23, 1976, rather than from the 1973 date of disability.
The referee dismissed the petition, stating that the decision of November, 1972, was res judicata. The wcab reversed in October, 1978, and remanded for a hearing on the merits. The wcab said the prior decision was res judicata "as to plaintiff’s physical condition through the date of hearing.” (Emphasis in original.) The Court of Appeals denied leave to appeal in December, 1978.
*718On remand, the referee entered an order denying benefits, stating that there had been no worsening or change in Askew’s condition. On appeal, the wcab, by order dated December 26, 1984, disagreed with the referee and, in a two to one decision, awarded continuing benefits from March 23, 1976.
The Court of Appeals granted leave to appeal on March 28, 1985, and reversed on June 12, 1986. We granted leave to appeal, limited to the issue of the application of the doctrine of res judicata in this case. Askew v Ann Arbor Public Schools, 428 Mich 857; 399 NW2d 397 (1987).
November, 1972.
MCL 418.851, 418.863; MSA 17.237(851), 17.237(863).
MCL 418.859; MSA 17.237(859). The statute was amended by 1985 PA 103; the quoted phrase now reads: "may hear the parties, together with such additional evidence as it may allow . . . .”
Askew v Ann Arbor Public Schools, unpublished opinion per curiam of the Court of Appeals, decided June 12, 1986 (Docket No. 82704).
" 'The general rule with respect to the effect upon the application of the principles of res judicata to decisions under workmen’s compensation acts, of a provision authorizing the modification of an award upon a showing of a change in the employee’s condition, is that a compensation award is an adjudication as to the condition of the injured workman at the time it is entered, and conclusive of all matters adjudicable at that time, but it is not an adjudication as to the claimant’s future condition and does not preclude subsequent awards or subsequent modifications of the original award upon a showing that the employee’s physical condition has changed. . . .’” Hlady v Wolverine Bolt Co, 393 Mich 368, 375-376; 224 NW2d 856 (1975) (emphasis supplied in Hlady). [Gose v Monroe Auto Equip, 409 Mich 147, 160-161; 294 NW2d 165 (1980).]
Dimensions of "Claim” for Purposes of Merger or Bar — General Rule Concerning "Splitting”
(1) When a valid and final judgment rendered in an action extinguishes the plaintiffs claim pursuant to the rules of merger or bar (see §§ 18, 19), the claim extinguished includes all rights of the plaintiff to remedies against the defendant with respect to all or any part of the transaction, or series of connected transactions, out of which the action arose.
(2) What factual grouping constitutes a "transaction,” and *721what groupings constitute a "series,” are to be determined pragmatically, giving weight to such considerations as whether the facts are related in time, space, origin, or motivation, whether they form a convenient trial unit, and whether their treatment as a unit conforms to the parties’ expectations or business understanding or usage. [1 Restatement Judgments, 2d, § 24, p 196.]
We recognize that the view expressed in this wcab opinion may not be shared by all members of the wcab. There is, however, no decision of the wcab to the contrary.
Ann Arbor Public Schools relies on the statement of a member of the wcab who filed a concurring opinion in another case, stating the procedure to be followed when an employer, in that case, or an employee files a new petition on the basis of a change in physical condition after an initial decision and award or denial by a referee. In this case no such petition was filed.
We regard as noteworthy that the wcab’s decision in the instant case, on the question whether a petition to take additional evidence must be filed with the wcab, during the pendency of the appeal before *722it, to avoid the bar of res judicata where there has been a change in physical condition during the pendency of the appeal, was written by the chairman of the wcab and signed by four other members without qualification.
See text accompanying n 5.
When the doctrine of res judicata has been invoked to bar a claim not presented, the party against whom it has been applied, generally if not invariably, has had an opportunity to present as of right the claim not presented, but failed to do so. In the instant case, Askew did not have a right to present a claim for continuing benefits during the course of her appeal to the wcab from the 1972 referee decision. While we do not predicate decision on the basis that she did not have a right to so present her claim, we do not wish to be understood as intimating that the doctrine of res judicata may be invoked in respect to a claim not presented where the claim may not be presented as of right.
See MCL 418.859; MSA 17.237(859); Kostamo v Marquette Iron Mining Co, 405 Mich 105, 135; 274 NW2d 411 (1979).
MCL 418.861a; MSA 17.237(861a). See Civil Service Comm v Dep’t of Labor, 424 Mich 571; 384 NW2d 728 (1986).
MCL 418.861a(12); MSA 17.237(861a)(12).
See n 12.
Hlady, supra, 376.
Payment of seventy percent of weekly benefits awarded by a referee is required during the pendency of an appeal to the wcab. MCL 418.862; MSA 17.237(862).