90 N.Y.2d 110 (1997)
A teacher’s actual service as a substitute, rather than the anticipated duration of the replaced teacher’s absence, determines whether the teacher qualifies as a “regular substitute” for purposes of earning Jarema credit toward tenure.
Summary
Mindy Speichler, a special education teacher, sought tenure by estoppel, arguing that her prior substitute teaching service should count towards her probationary period. The Board of Cooperative Educational Services (BOCES) denied her claim, arguing that her service as a “per diem substitute” filling in for teachers on indefinite leave did not qualify as “regular substitute” service under Education Law § 2509(1)(a). The Court of Appeals reversed the Appellate Division’s decision against Speichler, holding that the nature of the service actually performed, rather than the expected duration of the replaced teacher’s absence, determines whether a substitute teacher is considered a “regular substitute” eligible for Jarema credit.
Facts
Mindy Speichler began working as a per diem substitute teacher for BOCES in November 1989, filling in for a regular teacher moved to a different assignment for an indeterminate period. She continuously taught the class. In March 1990, she was formally appointed as a regular substitute due to another teacher’s child care leave, though she remained in the same classroom. The following school year, she again worked as a per diem substitute, covering another teacher’s class while he was temporarily assigned to another role. In December 1990, she was formally appointed to a probationary teaching position. In October 1993, BOCES notified her that she would not be recommended for tenure, leading to this legal challenge.
Procedural History
Speichler initiated a CPLR article 78 proceeding, arguing she had achieved tenure by estoppel because her prior substitute service should count toward her probationary period. The Supreme Court granted her petition, reinstating her with tenure. The Appellate Division reversed, finding her per diem substitute service did not qualify as regular substitute service. Speichler appealed to the Court of Appeals.
Issue(s)
Whether a teacher’s service as a substitute for a teacher on leave for an indefinite period can be credited towards the probationary period required for tenure under Education Law § 2509(1)(a) as “regular substitute” service.
Holding
Yes, because the actual nature and continuity of the substitute service, not the anticipated duration of the replaced teacher’s absence, define the ambiguous statutory term “regular substitute.”
Court’s Reasoning
The Court reasoned that the term “regular substitute” in Education Law § 2509(1)(a) is ambiguous and not defined by statute. While BOCES argued that “regular substitute” status requires a definite leave of absence for the replaced teacher, the Court disagreed, finding that the focus should be on the actual service performed by the substitute teacher. Citing prior decisions from the Commissioner of Education, the Court noted that the key factor is whether the teacher provided continuous service for at least one school term. The Court emphasized the principle that tenure rules should be interpreted broadly in favor of the teacher, prioritizing function over form. Citing Ricca v. Board of Educ., the court reiterated that the tenure system should not be undermined by technical obstacles. The Court acknowledged BOCES’ argument that a definite term requirement promotes predictability, but concluded that it is more important to protect qualified teachers from losing tenure rights due to manipulable labels. The Court concluded that Speichler’s continuous teaching for a full semester qualified her for Jarema credit, entitling her to tenure. The dissenting judges argued that the majority’s retrospective, functional criterion for determining ‘regular substitute’ status contradicted the Commissioner of Education’s interpretation and would create more uncertainty.