(concurring, with whom Marshall, C.J., and Sos-man, J., join). The school district of Beverly (district) appealed from the order of a Superior Court judge affirming an arbitration award reinstating James Geller, a sixth grade teacher, who had been discharged for physically and verbally abusing his students on multiple occasions. The district asserts that the award reinstating Geller was beyond the arbitrator’s authority, contrary to the best interests of the students, and violative of a public policy prohibiting teachers from using physical force against students.
The Superior Court judge concluded that the arbitrator acted within the scope of his authority in ordering reinstatement. The Appeals Court reversed and vacated the arbitrator’s award, holding that Geller’s reinstatement offended “a clear and well defined public policy against the use of physical force, however *225slight, by a teacher against students.” School Dist. of Beverly v. Geller, 50 Mass. App. Ct. 290, 297 (2000). This court granted Geller’s application for further appellate review.
This is the first occasion in which we have considered the dismissal of a teacher under the provisions of G. L. c. 71, § 42, as appearing in St. 1993, c. 71, § 44, the Education Reform Act of 1993.1 I believe that the arbitrator exceeded the authority granted him by G. L. c. 71, § 42, when he substituted his own judgment as to proper discipline for that of the district, after finding in substance that the district had sustained its burden of proving that Geller had engaged in “conduct unbecoming a teacher,” one of the statutorily enumerated bases on which teachers with professional teacher status can be dismissed.2
*2261. Factual background. Geller was employed as a teacher in the district for over twenty years and had attained professional teacher status (formerly known as tenure), as defined in G. L. c. 71, § 41. He was dismissed in October, 1996, by the principal of the school in which he taught, with the approval of the superintendent of schools, for conduct unbecoming a teacher after it was determined that Geller had used physical force against students on three separate occasions. Geller appealed from his discharge to an arbitrator pursuant to G. L. c. 71, § 42, fourth par.
After conducting an evidentiary hearing the arbitrator found that Geller had engaged in the conduct alleged by the district and that “[pjushing [students] against a wall and yelling in their faces is totally inappropriate.”* 3 He further found that Geller’s *227conduct was “unacceptable” and “cannot be condoned.” With respect to the penalty of dismissal, the arbitrator noted that, “once having determined that misconduct occurred, the School Department has substantial discretion in determining the level of discipline to be imposed.” He concluded, however, that the appropriateness of the discipline had to be measured against more than twenty years of service, no prior disciplinary problems, and good prior evaluations. Without elaboration, he found that, “[i]t is in the best interest of the students that a teacher of Mr. Geller’s accomplishments and experienced [sz'c] be retained.” He then ruled that the district had “just cause to impose severe discipline, short of discharge,” directed that “the decision in this case constitutes a final warning to [Geller],” and ordered that Geller be reinstated at the start of the 1997-1998 school year without back pay. In his award the arbitrator found that “the dismissal of James Geller [was] not for just cause within the meaning of Chapter 71, Section 42,” and in effect reduced Geller’s dismissal to an unpaid suspension of approximately one school year.
2. Standard of review. A teacher with professional teacher status, such as Geller, can be dismissed only for “inefficiency, incompetency, incapacity, conduct unbecoming a teacher, insubordination or failure ... to satisfy teacher performance standards ... or other just cause” (emphasis added). G. L. c. 71, § 42, third par. If a teacher with this status is discharged, he or she may seek review of the dismissal by filing a petition for arbitration. G. L. c. 71, § 42, fourth par. At an arbitration hearing, the school district has the burden of proving the grounds for dismissal, in this case, conduct unbecoming a teacher. G. L. c. 71, § 42, fifth par. In determining whether the school district has satisfied its burden, the arbitrator must *228consider the best interests of the pupils in the district and the need to elevate standards of performance. Id. The arbitrator is required to issue a “detailed statement of the reasons for [his] decision.” G. L. c. 71, § 42, sixth par.
The arbitrator’s decision is subject to judicial review as provided in G. L. c. 150C (concerning collective bargaining agreements to arbitrate). G. L. c. 71, § 42, sixth par. Our role in reviewing an arbitrator’s award pursuant to G. L. c. 150C, § 11, is limited. Bureau of Special Investigations v. Coalition of Pub. Safety, 430 Mass. 601, 603 (2000), quoting Concerned Minority Educators of Worcester v. School Comm. of Worcester, 392 Mass. 184, 187 (1984). Unlike our review of factual findings and legal rulings made by a trial judge, we are bound by an arbitrator’s findings and legal conclusions. “The courts are not authorized to reconsider the merits of an award even though the parties may allege that the award rests on errors of fact or on misinterpretation of the contract.” United Paperworkers Int’l Union v. Misco, Inc., 484 U.S. 29, 36 (1987) (Misco). See Plymouth-Carver Regional Sch. Dist. v. J. Farmer & Co., 407 Mass. 1006, 1007 (1990); School Comm. of Waltham v. Waltham Educators Ass’n, 398 Mass. 703, 705 (1986) (arbitrator’s decision may not be vacated on error of fact or error of law). “Even a grossly erroneous [arbitration] decision is binding in the absence of fraud” (citation omitted). Trustees of the Boston & Me. Corp. v. Massachusetts Bay Transp. Auth., 363 Mass. 386, 390 (1973). This narrow scope of judicial review reflects a strong public policy favoring arbitration. Plymouth-Carver Regional Sch. Dist. v. J. Farmer & Co., supra at 1007. However, if, on review, the court finds that an arbitrator has exceeded his authority in fashioning an award, the court is required to vacate it. G. L. c. 150C, § 11 (a) (3).4 Local 589, Amalgamated Transit Union v. Massachusetts Bay Transp. Auth., 392 Mass. 407, 410-411 (1984) (whether arbitrator exceeded scope of his authority is question always open to judicial review).
3. Arbitrator’s scope of authority. The power and authority of an arbitrator is ordinarily derived entirely from a collective *229bargaining contract, and he violates his obligation to the parties if he substitutes “ ‘his own brand of industrial justice’ for what has been agreed to by the parties in that contract.” Georgia-Pacific Corp. v. Local 27, United Paperworkers Int’l Union, 864 F.2d 940, 944 (1st Cir. 1988), quoting United Steelworkers v. Enterprise Wheel & Car Corp., 363 U.S. 593, 597 (1960). An arbitrator cannot “transcend[] the limits of the contract of which the agreement to arbitrate is but a part.” Plymouth-Carver Regional Sch. Dist. v. J. Farmer & Co., supra, quoting Lawrence v. Falzarano, 380 Mass. 18, 28 (1980). Stated differently, an arbitrator’s “award is legitimate only so long as it draws its essence from the collective bargaining agreement” that he is confined to interpret and apply. United Steelworkers v. Enterprise Wheel & Car Corp., supra at 597. School Comm. of Waltham v. Waltham Educators Ass’n, supra at 706-707. In performing his responsibilities, the arbitrator exceeds his authority if he ignores the plain language of the contract. Misco, supra at 38.
In this case the source of the authority to arbitrate the dismissal of a teacher is a statute, not a collective bargaining contract. This important difference informs this court’s determination of how the arbitrator’s powers are to be ascertained and interpreted.
In the collective bargaining context, the arbitrator is ordinarily empowered to interpret the underlying contract and the extent of his powers thereunder. Such authority comes from the parties having agreed to it in the contract itself and is consistent with the notion that arbitrators have special expertise in the interpretation of collective bargaining agreements. See School Comm. of Danvers v. Tyman, 372 Mass. 106, 115 (1977) (interpreting collective bargaining agreement ordinarily task for arbitrator and not court); School Comm, of Hanover v. Curry, 369 Mass. 685, 685 (1976) (“We do not review the arbitrator’s interpretation of the agreement, since that subject is committed to the arbitrator by the agreement”). See also Misco, supra at 37-38 (“it is the arbitrator’s view of the facts and of the meaning of the contract that [the parties] have agreed to accept”). But as the United States Supreme Court noted long ago, “the specialized competence of arbitrators pertains primarily to the *230law of the shop, not the law of the land.” Alexander v. Gardner-Denver Co., 415 U.S. 36, 57 (1974), citing United Steelworkers v. Warrior & Gulf Navigation Co., 363 U.S. 574, 581-583 (1960). “Where the determinations to be made are primarily issues of public law, the arbitrator possesses no special expertise . . . .” School Comm. of Hanover v. Curry, 3 Mass. App. Ct. 151, 156 (1975), S.C., 369 Mass. 683 (1976) (no justification for allowing arbitrator to determine school committee’s statutory rights). See Massachusetts Bay Transp. Auth. v. Local 589, Amalgamated Transit Union, 406 Mass. 36, 40 (1989), citing Local 589, Amalgamated Transit Union v. Massachusetts Bay Transp. Auth., 392 Mass. 407, 411 (1984) (“court, upon review, need not defer to arbitrator’s interpretation of relevant statutes”). Hence, the responsibility for interpreting the meaning of G. L. c. 71, § 42, and the scope of the arbitrator’s authority thereunder remains with the court. It cannot be ceded to the arbitrator by agreement of the parties,5 and has not been ceded to the arbitrator in the statute.
4. Analysis. The principal dismissed Geller for conduct *231unbecoming a teacher based on three incidents of abuse (and a prior warning) that he contended supported that ground for dismissal. Conduct unbecoming a teacher is specifically identified in the statute as a ground on which dismissal is proper. The arbitrator found that Geller had engaged in the conduct with which he was charged. The fact that the arbitrator characterized the conduct as “unacceptable” and not “unbecoming,” and that he did not use the phrase “conduct unbecoming a teacher” in his finding, but referred to it as conduct that “cannot be condoned,” is not determinative. He found facts and described those facts in a manner that clearly establishes Geller’s conduct to be “conduct unbecoming a teacher,”6
Having found that Geller engaged in serious misconduct that the statute specifically identifies as proper grounds for dismissal, the arbitrator proceeded to apply an additional “just cause” analysis — weighing Geller’s repeated misconduct against a more than twenty-year career of good performance — in an effort to gauge whether the punishment should be modified. In doing so he ignored the plain words and import of the statute. In essence, he substituted his own judgment of what the penalty should be for that of the district, and thereby acted beyond his authority.7
In concluding that the arbitrator acted beyond the authority
*232vested in him by G. L. c. 71, § 42, I interpret the statute in accord with the interpretation many courts have given to collective bargaining agreements that identify specific grounds warranting dismissal. In reviewing arbitration awards arising out of such agreements, courts have consistently held that, when an agreement specifically enumerates grounds for dismissal, the arbitrator does not have the authority to judge whether discharge is an excessive penalty for the violation committed. Fogel, Court Review of Discharge Arbitration Awards, 37 Arb. J. 22, 25-28 (No. 2, 1982). This is the case even when the agreement also provides for dismissal on just cause.* ******8
*233Our statute is analogous to such an agreement. It enumerates six specific grounds on which dismissal may be based, in addition to “other just cause.” In this context, the six specific grounds set forth in the statute constitute adequate grounds for dismissal independent of “other just cause.”* *******9 Stated conversely, *234the six specifically enumerated grounds constitute “just cause” for dismissal by clear statutory mandate. From either perspective, a proper interpretation of the statute precludes the arbitrator from conducting a further “just cause” analysis (e.g., weighing the teacher’s prior record against the misconduct for the purpose of justifying a different sanction) once he has found that one of the enumerated grounds for dismissal has been proved. See cases cited in note 8, supra.10
While parties to a private collective bargaining agreement may choose to give an arbitrator a great deal of discretion and authority to determine what sanctions to impose for misconduct, G. L. c. 71, § 42, does not, at least not as to dismissals based on the conduct specifically enumerated in G. L. c. 71, § 42, third par. If the Legislature had intended to cede this authority to an arbitrator, it could readily have done so.11 The principal, with the approval of the superintendent of schools, retains the sole statutory authority to determine whether to discharge, demote, or discipline teachers for the misconduct which the Legislature has specifically identified.12 In the absence of such *235authority, the arbitrator exceeds his powers when he does so.13
Because the arbitrator erroneously applied a further just cause analysis to misconduct that was both enumerated in the statute as a proper basis for discharge and proved by the district, and because he substituted his judgment for that of the district by imposing “severe discipline, short of discharge,” the arbitrator exceeded the scope of his authority.
5. Best interests of the students. General Laws c. 71, § 42, fifth par., requires that the arbitrator “consider the best interests of the pupils in the district and the need for elevation of performance standards” in determining whether the district has proved grounds for dismissal. This simply stated requirement is a direct reminder that the purpose of the Education Reform Act of 1993, from its billions of dollars in additional financial aid to local school systems, to its establishment of teacher performance standards, is to improve the education provided to the students in the classrooms of our public schools. It is also a reminder that the teacher dismissal statute is not only about the relationship between employer and employee, it is about the education of students. Their stake in the dismissal of inadequate teachers must now be specifically taken into account14 and, accordingly, their best interests and the elevation of performance standards *236are considerations that might properly influence the ultimate conclusion of the arbitrator in a particular case.15
In this case, after weighing Geller’s misconduct against his more than twenty years of teaching service to ascertain whether dismissal was too severe a penalty (and apparently concluding that it was), the arbitrator simply recites in his decision that it is also “in the best interest of the students that a teacher of Mr. Geller’s accomplishments and experienced [szc] be retained.” It is unclear how or whether this cursory conclusion regarding an important statutory consideration contributed to the arbitrator’s ultimate determination that “[t]he dismissal of James Geller was not for just cause within the meaning of Chapter 71, Section 42.” Whether the statement was intended merely as confirmation that this required consideration had been made and was consistent with the outcome of the arbitrator’s “just cause analysis,” or whether it was an important factor in tipping the scales against dismissal, I cannot ascertain from the decision. I need not address this issue because, as set forth above, it is my conclusion that the arbitrator exceeded his authority by applying a further just cause analysis to the proven misconduct in the first instance.
For these reasons I concur in the decision to vacate the Superior Court judgment and would vacate the arbitrator’s award as well.
The Education Reform Act of 1993, St. 1993, c. 71, made substantial changes to the governance structure and financing of the public school system in the Commonwealth. These changes were enacted to ensure: “(1) that each public school classroom provided the conditions for all pupils to engage fully in learning as an inherently meaningful and enjoyable activity without threats to their sense of security or self-esteem, (2) a consistent commitment of resources sufficient to provide a high quality public education to every child, (3) a deliberate process for establishing and achieving specific educational performance goals for every child, and (4) an effective mechanism for monitoring progress toward those goals and for holding educators accountable for their achievement.” G. L. c. 69, § 1, as appearing in St. 1993, c. 71, § 27. G. L. c. 69, § 1A, as appearing in St. 1993, c. 71, § 28.
To further these goals, statutory changes were made to the statute governing teacher demotions and dismissals, G. L. c. 71, § 42. These changes included (1) transferring from school committees to school principals and superintendents the responsibility for dismissing teachers; (2) expanding the statutorily enumerated grounds for dismissal to include failure to satisfy teacher performance standards, and changing the catchall ground from other “good” cause to other “just” cause; (3) depoliticizing and streamlining the dismissal process by requiring that contested dismissals proceed directly to arbitration, where timelines for decisions and detailed statements of supporting reasons are mandated; (4) providing for limited rather than de novo review of dismissal decisions (as confirmed or not by arbitration) in the Superior Court; and (5) requiring arbitrators specifically to take into account the best interests of students and the need for the elevation of performance standards in determining whether a school district has met its burden of proving grounds for dismissal.
I reach this conclusion based on our interpretation of the authority granted to the arbitrator by G. L. c. 71, § 42, an issue raised by the parties, and a task necessary to deciding the meaning and application of the statute to the facts of this case. However, although I agree with the district that the arbitrator exceeded his powers, I do so for reasons different from those adopted by the *226Appeals Court and argued by the district either here or in the courts below, but advanced and argued in the amicus briefs.
The facts found by the arbitrator, as gleaned from the Appeals Court opinion, School Dist. of Beverly v. Geller, 50 Mass. App. Ct. 290, 291-292 (2000), are as follows:
1. In November, 1995, Geller yelled at his students in the classroom, making them feel uncomfortable. A letter from a parent to the district resulted in a meeting, in the course of which Geller admitted to sometimes having an “outburst” and that he was working on “calming down.” The assistant principal, who was present at the meeting, cautioned Geller that the issue was serious and that, if such conduct was taking place in the classroom, it should not be.
2. Subsequently, in the course of one week in May, 1996, Geller was involved in three separate incidents in which he used physical force against three of his sixth grade students. The arbitrator found the witnesses’ versions of the following events to be credible:
a. On May 22, 1996, one student, whom we shall call J.S., got up in class to retrieve a pencil that had fallen on the floor. Geller, after yelling at the student, took him by the elbow and “directed” him, very, very fast, out of the classroom and into the hallway. Once in the hall, Geller pushed or threw J.S. against a locker and then pushed J.S.’s head, forcing him against the wall next to the lockers. Geller grabbed J.S. by the shirt (around the collar) and threw him against the locker. A school nurse testified that two days later she observed a bruise on J.S.’s elbow, consistent with his being held in a forceful way.
b. On May 23, 1996, another sixth grade student, whom we shall call J.F., was standing near a chair in the classroom when Geller ordered all students to be seated. J.F. did not sit immediately, and Geller approached him from the rear, poking J.F. in the back three times in rapid succession. When J.F. turned, Geller shoved him with both hands; the force was sufficient to knock J.F. off balance and he fell on top of a desk. Geller then grabbed J.F. by the hand and *227pulled Mm over to the teacher’s desk. J.F. told his mother, who reported the incident to the principal. J.F. felt afraid of Geller as a result of the mcident and did not return to Geller’s class for the rest of the year.
c. The third incident occurred on or about May 27, 1996. Another student, whom we shall call C.R., admitted humming, with a view to distracting Geller. Geller grabbed C.R. by the shoulders and pushed Mm hard against the door. Geller then opened the door, pushing C.R. into the hallway and up against a locker, wMle screammg and yelling at him. C.R. reported the incident to his mother, who notified the authorities.
General Laws c. 150C, § 11 (a), provides in pertinent part that “the superior court shall vacate an award if. . . (3)the arbitrators exceeded their powers.”
The arbitrator describes the issue submitted to him for decision as follows:
“Was the dismissal of James Geller for just cause within the meaning of Chapter 71, Section 42? If not, what shall be the remedy?”
The parties do not contest this formulation. Regardless of how the parties framed the issue, the court must decide whether the arbitrator exceeded his authority in framing his award and in substituting an alternative remedy for that imposed by the district. See Metro Chevrolet, Inc. v. Union de Tronquis-tas de P.R., 835 F.2d 3, 5 (1st Cir. 1987) (stipulated issue for arbitration should not be interpreted to confer broader authority on arbitrator than that set forth in collective bargaining agreement); County College of Morris Staff Ass’n v. County College of Morris, 100 N.J. 383, 394 (1985) (regardless of how issue framed by arbitrator, even in face of no apparent concern of parties, “the Court and the arbitrator are compelled by the constraints of the contract”); Ohio Office of Collective Bargaining v. Ohio Civil Serv. Employees Ass’n, Local 11, 59 Ohio St. 3d 177, 184 (1991) (court rejected parties’ description of issues stipulated to arbitrator because if accepted it would permit arbitrator to exceed authority).
Insofar as the source of arbitral authority in the case before us derives from a statute rather than a contract, the parties could not properly authorize the arbitrator to act beyond his statutory authority in any event. See School Comm. of Hanover v. Curry, 3 Mass. App. Ct. 151, 155-156 (1975), S.C., 369 Mass. 683 (1976) (issue of abolition of teaching position was by statute committed to school committee and should not have been submitted to arbitrator, therefore decision was beyond arbitrator’s authority even if within scope of reference given to arbitrator by parties).
See, e.g., Director of the Div. of Employment Sec. v. Mattapoisett, 392 Mass. 858, 859 (1984) (teacher who pushed student, behaved in “argumentative and overbearing manner,” and pushed fellow teacher, engaged in conduct unbecoming teacher); MacKenzie v. School Comm. of Ipswich, 342 Mass. 612, 616 (1961) (teacher’s profane utterance was improper and unbecoming conduct); Kurlander v. School Comm. of Williamstown, 16 Mass. App. Ct. 350, 357 (1983) (teacher’s behavior, much of it in front of students, was “insolent, abusive, loud and out of control,” and thus supported charge of unbecoming conduct). See also Conward v. Cambridge School Comm., 171 F.3d 12, 20 (1st Cir. 1999) (shoving of student by teacher conduct “inappropriate for the scholastic environment”).
We note that the arbitrator found Geller’s actions to constitute serious misconduct (“totally inappropriate,” “unacceptable,” which “cannot be condoned”), a finding consistent with the evidence adduced at the arbitration hearing. This is not the case of an arbitrator finding a teacher to have engaged in minor misconduct that, however, nominally fit within a category on which dismissal could be based. In such circumstances, an arbitrator’s finding that the conduct did not rise to the level of misconduct contemplated by the statute as a ground for dismissal is one that would likely lie within the scope of his authority.
See Warrior & Gulf Navigation Co. v. United Steelworkers, 996 F.2d 279, 281 (11th Cir. 1993), cert, denied, 511 U.S. 1083 (1994) (in agreement which required “just cause” for termination and also listed conduct for which an employee would be subject to discharge, arbitrator lacked discretion to reduce discharge to suspension for listed conduct); Delta Queen Steamboat Co. v. District 2 Marine Eng’rs Beneficial Ass’n, 889 F.2d 599, 601, 604 (5th Cir. 1989), cert, denied, 498 U.S. 853 (1990) (if agreement provides for termination for “proper cause” and includes nonexhaustive list of offenses that would constitute cause, arbitrator is not free to measure proved conduct against forty years of service and override termination decision); Georgia-Pacific Corp. v. Local 27, United Paperworkers Int’l Union, 864 F.2d 940, 945 (1st Cir. 1988) (“just cause” is but one ground for discharge to be considered independently of other contractually enumerated grounds for discharge; deciding case solely on just cause grounds in spite of other enumerated grounds is “patent example of arbitral excess,” and arbitrator does not have such unfettered discretion); S.D. Warren Co. v. United Paperworkers’Int’l Union, Local 1069, 845 F.2d 3, 8 (1st Cir.), cert, denied, 488 U.S. 992 (1988) (where agreement provided for discharge on “proper cause” and identified specific causes upon which discharge could be based, arbitrator not authorized to determine different remedy for proved conduct); Metro Chevrolet, Inc. v. Union de Tronquistas de P.R., supra (when general “just cause” provision for discharge in agreement is coupled with specific conduct provision upon which discharge may be based, appropriateness of penalty for that conduct is removed from consideration and is outside scope of arbitrator’s review); International Bhd. of Firemen & Oilers, Local No. 935-B v. Nestle Co., 630 F.2d 474, 476 (6th Cir. 1980) (not for arbitrator to decide that discharge is too severe penalty for insubordination that he found because insubordination identified in contract as grounds for termination); Mistletoe Express Serv. v. Motor Expressmen’s Union, 566 F.2d 692, 695 (10th Cir. 1977) (arbitrator may not construe “just cause” provision of labor contract to include progressive discipline requirement when contract provisions explicitly state failure of employee to meet certain condition is grounds for discharge; use of words “may discharge” gives employer, not arbitrator, option to discharge for stated grounds); County College of Morris Staff Ass’n v. County College of Morris, 100 N.J. 383, 394-395 (1985) (where agreement provided for dismissal of employees for “just cause,” and included *233a list of conduct for winch employees could be discharged, arbitrator exceeded authority by reading into agreement requirement for progressive discipline and reducing termination to suspension); Ohio Office of Collective Bargaining v. Ohio Civil Serv. Employees Ass’n, Local 11, 59 Ohio St. 3d 177, 182-183 (1991) (agreement provided that discipline not to be imposed except for “just cause,” and that abuse of patient was grounds for termination; arbitrator exceeded authority by grafting a further just cause requirement onto clause governing termination for abuse and reducing penalty). See also General Drivers, Warehousemen & Helpers, Local 89 vs. Willamette Indus., Inc., United States Dist. Ct. No. 98-5476 (6th Cir. July 6, 1999) (where agreement provided that employee could be discharged for “good cause” or violation of specified rules, arbitrator had no authority to modify discharge penalty on finding violation of such rules); Marathon Oil Co. vs. Cylinder Gas, Chem. Petroleum, Distillery, Auto Serv., United States Dist. Ct. No. 97-1780 (6th Cir. Sept. 25, 1998) (agreement provided for discharge only for “just cause,” but listed certain grounds for discharge including dishonesty; arbitrator exceeded authority in applying additional just cause analysis and reducing discharge for dishonesty because of employee’s length of service and clean record; if dishonesty identified as a basis for discharge it is “just cause”).
The word change in the statute from “other good cause” to “other just cause” cannot be read so broadly as to have limited and modified the specifically enumerated grounds for dismissal, or to have given to the arbitrator authority to substitute “his own brand of industrial justice” for that of the responsible public authority.
The words “or other good cause” contained in the previous version of the statute as a basis for dismissal had been interpreted as an additional category, expanding but not modifying the enumerated bases. See, e.g., Faxon v. School Comm. of Boston, 331 Mass. 531, 533 (1954) (“conduct unbecoming a teacher” and “other good cause” are distinct designations in G. L. c. 71, § 42); Graves v. School Comm. of Wellesley, 299 Mass. 80, 85 (1937) (dismissal in conformity with G. L. c. 71, § 42, may be done “only on certain specified grounds or for ‘other good cause’”). There is no reason why the words “or other just cause” should be interpreted differently. It is reasonable, however, to conclude from the substitution of the word “just” for “good” that the Legislature intended to limit the broad range of conduct that had previously been considered as warranting dismissal in this catchall category, to serious misconduct. The words “good cause” have long been defined as “any ground which is put forward [by the supervising authority] in good faith and which is not arbitrary, irrational, unreasonable, or irrelevant to the . . . task of building up and maintaining an efficient school system.” Rinaldo v. School Comm. of Revere, 294 Mass. 167, 169 (1936). By comparison, the words “just cause” have a somewhat different meaning in the public employment *234arena, i.e., “substantial misconduct which adversely affects the public interest.” Murray v. Second Dist. Court of E. Middlesex, 389 Mass. 508, 514 (1983). Leominster v. International Bhd. of Police Officers, Local 338, 33 Mass. App. Ct. 121, 126 (1992).
“where a collective bargaining agreement specifies certain behavior as just cause for discharge, courts will vacate an arbitration award that modifies or annuls a discharge assessed under the specified cause.” Fogel, Court Review of Discharge Arbitration Awards, 37 Arb. J. 22, 25 (No. 2, 1982).
In § 42 the arbitrator is not empowered to impose a different remedy for proved misconduct. If the arbitrator finds that dismissal was improper, he may then take appropriate remedial action including awarding “back pay, benefits, reinstatement, and any other appropriate non-financial relief or any combination thereof.” G. L. c. 71, § 42, sixth par.
The interests at stake in teacher dismissals reach beyond the employer and employee. As forcefully stated in a case decided prior to the Education Reform Act of 1993, “[mjanifestly one of the most important duties involved in the management of a school system is the choosing and keeping of proper and competent teachers. The success of a school system depends largely on the character and ability of the teachers. Unless a school committee has authority to employ and discharge teachers it would be difficult to perform properly its duty of managing a school system.” Davis v. School Comm. of Somerville, 307 Mass. 354, 362 (1940). While the Education Reform Act shifted personnel authority from the school committee to superintendents and principals, it did not alter the long-standing deference to managerial prerogative with respect to the assessment of teacher qualifications or the statutory power to *235discharge teachers. See, e.g., Higher Educ. Coordinating Council/Roxbury Community College v. Massachusetts Teachers Ass’n/Mass. Community College Council, 423 Mass. 23, 31 n.8 (1996). Decisions concerning managerial rights in the public sector are qualitatively different from those in the private sector, not only because of the presence of statutes regulating and limiting the public employer, but also because of the necessity of safeguarding public control over and accountability for such decisions. Nothing in the Education Reform Act delegates to arbitrators the critically important public responsibility for deciding when and whether to dismiss teachers whose conduct constitutes one of the causes for discharge enumerated in § 42. The discretion to dismiss or impose some other remedy remains with the responsible public officials.
That the arbitrator believed he had the authority to fashion his own remedies as if he were the principal is most apparent in that portion of his decision where he reinstates Geller without back pay but directs that this is to be “a final warning” to Geller. The statute does not give the arbitrator any authority to discipline, discharge, or issue “final warnings” to teachers.
That interest may not always be of significant consequence in a dismissal action. Theft or other gross misconduct outside of the classroom would justify dismissal based on other important principles, regardless of the teaching abilities of the teacher in question. But when a teacher is dismissed for conduct in *236the classroom, student interests are directly implicated and may well override typical employer-employee considerations. For example, it would not appear to be in the best interests of the students of a school district for a teacher to be retained who is no longer capable of effectively teaching or creating a positive learning environment — regardless of how many years of unblemished service he or she may have accumulated in the past, and no matter how such a period of prior service might be valued in a different employment context.
In such a case, we would expect the reasons for that conclusion to be set forth in detail in the “detailed statement of the reasons” required by G. L. c. 71, § 42, sixth par.