本研究立足于义务教育课程方案和课程标准（2022年版），探究素养导向下，大概念统领的初中生物学跨学科实践活动教学新常态的重要举措，推动育人方式变革，为学生未来发展奠基。本研究构建了大概念统领的跨学科实践活动理论框架，按照课时内容、自然单元、整合单元的顺序，开发模型建构、工程设计等不同类型的典型案例，检验并改进理论框架，提炼教学关键问题和实施策略。

本研究在文献研究和实践调研基础上，提出大概念统领的跨学科实践活动的设计模型、实施框架、评价方法，采用基于设计的研究范式，开展课时活动、单元活动、整合单元活动三轮教学实践，并依据活动效果分析，日趋完善和改进理论框架，提炼不同类型跨学科实践活动的关键问题和有效策略，回答大概念统领的跨学科实践活动如何设计、怎样实施、效果如何等研究问题，获得了较为丰硕的研究成果。首先，构建以“目标系统—问题系统—任务系统—评价系统”为核心，大概念统领的跨学科实践活动设计模型。其次，在引入活动、核心活动、总结活动教学实施三阶段的基础上，从教师和学生的角度，依据课内和课外、全员和演示、教师讲授和学生自主、活动封闭和开放等实施原则，建立大概念统领的跨学科实践活动实施框架。再次，确定测评活动效果的方法，基于课程标准的内容和要求，从活动成果的表现性评价、活动过程中档案袋评价、大概念的纸笔测试三种方式开展，同时结合调查访谈，从学生主观意识层面判断其对活动的态度。多种证据实现对活动效果的多方论证，并对设计模型和实施框架进行反馈。

第一轮教学实践中，将设计模型应用于“运动与防护”模型建构类课时活动。从效果分析可知，学生在形成“运动系统的结构与功能相适应，协调配合共同完成各项生命活动”的大概念方面获得一定成效。通过课堂实施和实践调研发现，设计模型较为复杂，需要在呈现样式、要素构成等方面做出适应性调整与简化，使其实用、好用；理论框架和构成要素的关系要进一步厘清；活动设计的交互过程、目标表述、教学评价等细节需要完善；更加凸显跨学科实践主题学习的特点。由此，对设计模型进行归纳整合与改进完善，并提出模型建构类活动实施策略。

以优化后的设计模型为基础，进行“育苗箱”工程设计类单元活动第二轮教学实践。跨学科实践活动驱动问题为“如何设计育苗箱，自制芽苗菜？”该活动包含 4 个子问题，对应大概念“植物有自己的生命周期”，次位概念“种子萌发的自身条件”“种子萌发的外界条件”。通过表现性评价和访谈结果可知，学生对相关大概念及其下位概念理解与掌握情况好，活动取得实际效果。教学实践证明，第二版设计模型相对于第一版更加简化和科学，但作为“模型”还需要提炼和概括。研究者对大概念统领的跨学科实践活动设计模型再次改进，并补充操作性定义，此外，提出工程设计类活动实施策略。

以再次优化的设计模型为基础，在“电子烟”整合单元活动中开展第三轮教学实践。跨学科实践活动挑战为“电子烟雾如何吸入人体？”分解为 4 个驱动性子问题，涵盖“人体的呼吸”“选择健康的生活方式”两个单元，对应“人体的结构与功能相适应，各系统协调统一，共同完成复杂的生命活动”“良好生活习惯是健康的重要保障”两个大概念。通过表现性评价、档案袋评价、纸笔测试和学生访谈结果可知，大概念统领的跨学科实践活动达成了设计理念，实现预期效果。在一系列教学研究的基础上，最终完善了理论模型，并成功指导教学实践。

大概念统领的跨学科实践设计模型，历经三轮教学实践改进，阐明大概念和跨学科实践活动的融合机制，可以为不同类型的跨学科实践活动提供设计依据。同时，以大概念统领的跨学科实践设计模型为理论指导，通过在初中生物学科中历时三个学期的典型案例探索，前后经过复习课中课时活动第一轮教学实践，常态课中单元活动第二轮教学实践，整合单元活动第三轮教学实践，并对整个过程进行详细记录和数据分析，提炼教学实施中重难点问题及解决策略，确定评价活动效果的方法，解决广大初中生物学教师在实践层面的困惑，明确活动实施的具体路径，形成一套相对完整的教学研究成果。总之，本研究系统探索了大概念与跨学科实践活动二者的实践性耦合途径，创新解决当下跨学科实践活动缺乏统领性目标，概念交叉和层级序列显性化表征途径不清晰，任务情境连贯性、梯度性不足等现实问题，具有重要的理论价值和实践意义。

Based on the Compulsory Education Curriculum Programme and the Curriculum Standards (2022 edition), this study explores the important initiatives of the new normal of literacy-oriented interdisciplinary practice activity teaching in junior high school
biology under the perspective of the Big Ideas unification, to push forward changes in the way of educating people and lay the foundation of the future development for students. This study constructs the theoretical framework for interdisciplinary practice
activities led by Big Ideas, develops different types of typical cases, such as modeling construction and engineering design, according to the order of lesson content, natural unit and integration unit, tests and improves the theoretical framework, and refines the
key teaching issues and implementation strategies.

On the basis of literature research and empirical research, this study constructs the design model, implementation framework and evaluation method of interdisciplinary practice led by Big Ideas, adopts the design-based research paradigm, carries out three rounds of teaching practice research on classroom activities, unit activities and integrated unit activities, and based on the analysis of the effects of those activities, refines the key issues and effective strategies of different types of interdisciplinary practical activities, the study also gradually refines and improves the theoretical model to answer the questions of how to design, how to implement and assess the effects of interdisciplinary practical activities under the umbrella of the Big Ideas. Till now the study has obtained relatively fruitful research results. First of all, we have constructed an interdisciplinary practical activity led by Big Ideas design model centered of “goal system - problem system - task system - evaluation system”. Secondly, based on the three-phase teaching and implementation process of introducing activities, core activities  and  summarizing  activities,  the  implementation  framework  of interdisciplinary practice activities led by the Big Ideas is established from the perspectives of teachers and students, based on the principles of implementation, such
as in-class and out-of-class, full involvement and demonstration, teacher teaching and student autonomy, and closed and open activities. Thirdly, the method of measuring the effect of the activities is determined, based on the content and requirements of the curriculum standards, which is accomplished in three ways: the expressive evaluation of the results of the activities, the evaluation of the archive bag in the process of the activities and the paper-and-pencil evaluation of the Big Ideas, and the combination of
the survey interviews to determine the attitudes of the students towards the practical activities from the level of their subjective consciousness. Multiple evidence realizes multiple arguments for the effectiveness of the activity and provides feedback on the
design model and implementation framework.

In the frist round of teaching practice, the design model was applied to the modeling-construction lesson activity “Sports and Protection”. The interdisciplinary practical activity was driven by the question “How to choose the right sports protective
gear?”. In the analysis of the results of the activity, it was found that the students were able to develop the Big Idea of “the structure and function of the motor system are
compatible and work together to accomplish various life activities”. Through classroom implementation and practical investigation, it is found that the design model is
relatively complex, and needs to be adapted and simplified in terms of presentation style and composition of elements, so as to make it practical and user-friendly; the relationship between the theoretical framework and components should be further
clarified, and the details of the interactive process of the activity design，teaching goal and teaching evaluation need to be perfected; and more characteristics of interdisciplinary practical thematic learning should be brought out. As a result, would
be integrated and improved design models and propose strategies for implementing modeling-construction activities.

In the second round of teaching practice, the optimized design model was used as the basis for the “Seedling Box” engineering-design unit activity. The interdisciplinary practical activity is driven by the question “How can we design a seedling box to make homemade sprouting vegetable?” It consists of four sub-questions, corresponding to the Big Idea “plants have their own life cycle”, and the secondary concepts “self-conditions
for seed germination” and “external conditions for seed germination”, Based on performance evaluation and interview results, it can be concluded that, the students generally have a good understanding and mastery of the Big Ideas and their subordinate concepts, and the activity has achieved practical results. This teaching practice has proved that the second version of the design model is more simplified and scientific than the first one, but as a “model” it still needs to be refined and generalized. Than the researcher improved the design model of interdisciplinary practical led by Big Ideas and added operational definitions. In addition, strategies for implementing activities in
the engineering-design category are proposed. In addition, proposed implementation strategies for engineering-design activities.

The third round of teaching practice was based on the re-optimized design model in the integrated unit activity “E-cigarettes”. The challenge of interdisciplinary hands-on activity was “How is E-cigarette smoke inhaled into the human body?” which was broken down into four driving sub-problems covering the two units of “Human Breathing” and “Choosing a Healthy Lifestyle”, and corresponding to the two concepts“Human body is structurally and functionally appropriate, and the systems are
coordinated and integrated to accomplish complex life activities”, “Good living habits are an important guarantee of health”. The results of the performance evaluation, portfolio evaluation, paper-and-pencil test and student interviews show that the interdisciplinary practical activities under the umbrella of the Big Ideas have reached the design concept and achieved the expected results. Based on a series of pedagogical research, the theoretical model was eventually refined and successfully guided teaching
practice.

The interdisciplinary practice design model led by the Big Ideas, which has been improved through three rounds of teaching practice, clarify the integration mechanism between Big Ideas and interdisciplinary practical activities, and can provide important
references for the design of different types of interdisciplinary practice activities. Meanwhile, taking the interdisciplinary practice design model led by the Big Ideas as a theoretical guide, the study explored typical cases in junior high school biology over a
period of three semesters, and went through the first round of teaching research on lesson activities in the revision class, the second round of teaching research on unit activities in the regular class, and the third round of teaching research on integration of
unit activities, and carried out a detailed record of the whole process and data analysis, demonstrating the important and difficult problems in the implementation of teaching and learning. The whole process is documented and analyzed in detail, showing the strategies and methods of solving the difficult problems in the teaching implementation, and forming a relatively complete set of teaching research results. In conclusion, this study systematically explores the practical coupling pathways between Big Ideas and
interdisciplinary practice activities, innovatively solves the practical problems such as the lack of overarching goals of interdisciplinary practice activities, unclear pathways of conceptual intersection and hierarchical sequence explicit representation, and insufficient task context coherence and gradient. It has important theoretical value and practical significance.