Purpose: As the school evaluator's role is multifaceted and the school elevator is the school principal's subordinate, this paper aims to present the school evaluator's complex conduct to achieve a better understanding of his or her functioning. Design/methodology/approach: Theoretical paper. Findings: The two critical dimensions connected to the purpose of this paper are introduced here: the school evaluators' credibility and the school principal's leadership style. Hence, the polymeric model displays four frames as follow: false evaluation, confusing evaluation, unreliable evaluation and trustworthy evaluation. Research limitations/implications: Although this is a theoretical paper, it can be transformed into a research paper by conducting a follow-up study. Practical implications: The increased responsibility that has been placed on schools and the demand for accountability as well as transparency have obligated schools to broaden and deepen the internal evaluation activities and those have led to the position of the school evaluator. This paper sheds light on the problem and suggests some relevant insights. Social implications: Evaluative culture in an organization requires deliberate efforts by the leadership to encourage the credible evaluators, to support their skillful and reliable work, and finally, to implement their conclusions even though management may find them tedious and time-consuming. School management that is driven by dishonest motivations (such as gaining power and control) may not only deprive the school of effective evaluation but may also harm the infrastructure of the institution and lead to its decline. Originality/value: This paper suggests an original model for school evaluation.