分析化学实验中设计性项目的梯度构建与实践构想——以“混合碱的测定”为例

Gradient Construction and Practical Conception of Design-Oriented Projects in Analytical Chemistry Experiments—A Case Study of “Determination of Mixed Alkalis”

摘要: 传统分析化学实验教学中，验证性实验占主导，学生往往“照方抓药”，导致创新意识与实践能力培养不足。针对这些问题，本文基于成果导向教育理念与建构主义学习理论，构建了“三阶递进”的设计性实验梯度教学模式。该模式以混合碱组分含量测定为载体，将实验教学划分为“基础验证–半设计–全设计”三个梯度，通过逐级撤除学习支架，引导学生从按图索骥逐步走向自主设计。本文系统比较了该模式与探究式教学、PBL教学等已有模式的异同，阐述了各梯度的教学目标、实施方案与评价策略，分析了操作层面的可行性与关键问题，并提出了配套的教学工具与效果评估方案。该模式为分析化学实验课程的设计性改革提供了可迁移、可操作的实施框架。

Abstract: Traditional analytical chemistry experimental teaching is dominated by confirmatory experiments, in which students often follow recipes mechanically, resulting in insufficient cultivation of innovative thinking and practical skills. To address these issues, this paper, grounded in Outcome-Based Education and Constructivist Learning Theory, proposes a “three-stage progressive” graded teaching model for design‑oriented experiments. Taking the determination of mixed alkali composition as the instructional vehicle, the model divides the experimental course into three tiers: basic verification, semi‑design, and full design. By gradually removing learning scaffolds, it guides students from executing prescribed protocols toward independent design. The paper systematically compares this model with existing approaches such as inquiry‑based teaching and Problem‑Based Learning, elaborating on the teaching objectives, implementation procedures, and assessment strategies for each tier. It also analyzes practical feasibility and key operational issues, and proposes supporting teaching tools and an evaluation plan for effectiveness. This model offers a transferable and actionable framework for the design‑oriented reform of analytical chemistry laboratory courses.