Mechanistic explanations, aiming to disclose details of entities and their activities, employ the act of unpacking which, inherently and paradoxically, produces explanatory gaps—pieces of undisclosed, undetailed mechanistic information. These gaps, termed explanatory black boxes, are often perceived as counterproductive to the teaching of mechanisms, yet are integral to it, and their cognizant use is a nuanced skill. Amidst the discourse on mechanistic reasoning in science education, this paper focuses on biology teachers’ perception of explanatory black boxes and the explicit discussion of them in their classroom. Using interviews with 11 experienced high-school biology teachers, we unraveled perceived affordances and constraints in teachers’ use of black boxes in the context of challenges in teaching mechanisms. Utilizing the pedagogical content knowledge (PCK) framework, we expose a nuanced interplay of considerations related to strategies, students, curriculum alignment, assessment, and orientation toward science teaching. A constant tension existed—with considerations supporting and opposing the use of both unpacking and black boxing as teaching strategies—both within and between PCK components. In contrast, contemplating the explication of black boxes led teachers to illustrate this strategy as an intermediate one, attenuating constraints of both unpacking and black-boxing strategies while also promoting teachers’ ability to align curricular items and endorse student agency. Implications for teacher training are discussed, emphasizing the need to make teachers aware of the involvement of black boxes in mechanistic reasoning, and familiarize them with black-box explication as an intermediate strategy that can enrich their pedagogy.

机械解释旨在揭示实体及其活动的细节，采用了拆包行为，这种拆包行为本质上是矛盾的，会产生解释间隙——未公开的、未详细的机械信息。这些差距被称为解释性黑匣子，通常被认为对机制的教学起反作用，但却是机制教学不可或缺的一部分，并且它们的认知使用是一项细致入微的技能。在科学教育中机械推理的讨论中，本文重点关注生物教师对解释性黑箱的看法以及在课堂上对其进行的明确讨论。通过对 11 名经验丰富的高中生物教师的采访，我们揭示了在教学机制面临挑战的背景下教师使用黑匣子的可感知性和限制。利用教学内容知识（PCK）框架，我们揭示了与策略、学生、课程调整、评估和科学教学方向相关的考虑因素的微妙相互作用。无论是在 PCK 组件内部还是在 PCK 组件之间，始终存在一种紧张关系，即支持和反对使用拆包和黑盒作为教学策略的考虑。相比之下，考虑黑箱的解释导致教师将这一策略说明为中间策略，减轻了拆包和黑箱策略的限制，同时也提高了教师调整课程项目和支持学生能动性的能力。讨论了对教师培训的影响，强调需要让教师意识到黑箱在机械推理中的参与，并使他们熟悉黑箱解释作为可以丰富他们的教学法的中间策略。