Developing and Testing a Model to Support Student Understanding of the Sub-Microscopic Interactions that Govern Biological and Chemical Processes

本项目设计、开发和测试连贯的跨学科教学材料，以支持高中生对原子和分子之间相互作用所涉及的力和能量的综合理解，并探索学生的学习如何随着时间的推移而进展。教材侧重于“K-12科学教育框架”（NRC, 2011）和“大学理事会大学成功标准”（College Board, 2009）中确定的物理科学核心思想。这两个研究问题是：(1)当学生经历了一套跨学科的教学材料，旨在帮助他们在非常小的尺度上实现与互动相关的重要学习目标时，学习如何随着时间的推移而进步？(2)各种学习活动如何支持综合理解的发展？该项目在密歇根州的三个学区实施，学生通常在科学方面不成功。其中两个学区的学生来自不同种族的城市社区；第三个服务于农村，主要是白人社区。为了开发和测试教学材料和相关评估，该项目与康科德联盟合作，采用了以构建为中心的设计过程（一个基于循证评估和学习目标驱动设计的原则过程）；使用物理和基于计算机的模型和模拟；并利用之前和正在进行的工作，假设学生在理解物质的结构、性质、相互作用和转化方面的学习进展。本课程共设四个教学单元：(1)电力导论，(2)水，(3)大分子，(4)生物分子，每个单元时长为两至六周。在可用性测试之后，单元要经过两个额外的阶段。第一阶段包括试点测试，至少有一名教师在两个地点，每个教室两个，每个单元产生100-120名学生的信息。第二阶段包括用更大的样本对装置进行现场测试。该项目使用幂度分析来确定样本量，测试了两种不同的单元序列：(a) 4名教师、8个教室和200名学生在学习生物或化学之前将这些单元作为一个学期的课程；(b) 4名教师，8个教室，200名学生在化学或生物课程的适当点上使用这些单元。来自同一学区的8名教师、16个教室和400名不使用该单元的学生作为对照组。采用混合方法收集和分析数据。数据收集策略包括：(a)前后测试，(b)单元嵌入评估，(c)学生的兴趣和态度，(d)评估学生在学习进程中的位置，(e)课堂观察，(f)学生课堂作业分析，以及(g)与学生和教师的访谈。数据解释策略包括：(a)对学生和教师从访谈中得到的回答进行编码，(b)识别模式，以及(c)使用项目反应理论（IRT）程序将学生的回答置于学习进程中。使用一系列方法来评估所使用的工具的效度和可靠性，包括：(A)结构效度，(b)内容效度和(c) IRT程序。项目外部评价涉及形成性和总结性两个方面。主要的项目成果包括：(a)一个以研究为基础并经过实地测试的学期课程，包括四个综合单元，有具体的目标、学习任务、说明和支持理解要点的现象、阅读材料和嵌入式评估；(b)与单元对齐的计算机模拟；(c)教师教材；(d)有效和可靠的工具来衡量学生的理解和态度；(e)一组研究手稿，重点关注新材料如何起作用，并促进学生学习关键的挑战性思想。

This project designs, develops, and tests coherent interdisciplinary instructional materials to support high school students' integrated understanding of the forces and energetics involved in interactions that occur between atoms and molecules, and explores how students' learning progresses across time. Instructional materials focus on physical science core ideas identified in "A Framework for K-12 Science Education" (NRC, 2011), and "College Board Standards for College Success" (College Board, 2009). The two research questions are: (1) How does learning progress over time when students experience a set of interdisciplinary instructional materials designed to help them advance toward important learning goals related to interactions at very small scales?; and (2) How do the various learning activities support the development of integrated understanding? The project is implemented in three Michigan school districts with students who traditionally do not succeed in science. Two of the school districts serve urban communities with ethnically diverse student populations; the third serves a rural, primarily Caucasian community. To develop and test instructional materials and associated assessments, the project joins efforts with the Concord Consortium and employs the Construct-Centered Design process (a principled process based on evidence-centered assessment and learning goal-driven designs); uses physical and computer-based models and simulations; and draws on previous and ongoing work on a learning progression of the hypothetical students' path in their understanding of the structure, properties, interactions, and transformations of matter. Four instructional units are produced: (1) Introduction to Electrical Forces, (2) Water, (3) Larger Molecules, and (4) Bio-Molecules, with a duration of two to six weeks each. After testing for usability, the units go through two additional phases. Phase I comprises pilot testing with at least one teacher at two sites, two classrooms each, yielding information from 100-120 students per unit. Phase II consists of field testing the units with a larger sample. Using a power analysis to determine sample size, the project tests two different sequences of the units: (a) four teachers, eight classrooms, and 200 students use the units as a single semester course before taking biology or chemistry; and (b) four teachers, eight classrooms, and 200 students use the units in appropriate points within a chemistry or biology course. Eight teachers from the same school districts, 16 classrooms, and 400 students who do not use the units, serve as the comparison group. A mixed-methods approach is used to collect and analyze data. Data collection strategies include: (a) pre- and post- tests, (b) unit-embedded assessments, (c) students' interest and attitudes, (d) assessments to place students in the learning progression, (e) classroom observations, (f) analysis of student classroom work, and (g) interviews with students and teachers. Data interpretation strategies include: (a) coding of students' and teachers' responses from interviews, (b) identification of patterns, and (c) using item-response theory (IRT) procedures to place students' responses in the learning progression. A range of methods are used to assess validity and reliability of instruments used, including: (a) construct validity, (b) content validity, and (c) IRT procedures. Project external evaluation addresses both formative and summative aspects. Key project outcomes include: (a) a research-informed and field-tested semester-long course comprising four integrated units with specific objectives, learning tasks, phenomena to illustrate and support understanding at key points, reading materials, and embedded assessments; (b) computer simulations aligned with the units; (c) educative materials for teachers; (d) valid and reliable instruments to measure students' understanding and attitudes; and (e) a set of research manuscripts focused on how the new materials work and promote student learning of key challenging ideas.