支架式教学案例

支架式教学案例 支架式教学 支架式教学是依据建构主义理论和最近发展区理论形成的现代教学设计理念，支持新课程倡导的自主学习、合作学习和探究学习。支架式教学的五大构成要素是:进入情境———引导探索———独立探索———协作学习———效果 评价 LEC评价法下载LEC评价法下载评价量规免费下载学院评价表文档下载学院评价表文档下载 。这五大要素即是贯穿于支架式教学中的五个基本组成环节。 教学案例——“滑动变阻器”(初中物理) 一、分析案例背景(搭脚手架) 变阻器是电路中的一个重要元件。由于变阻器的部件较多，接法又有多种，而且在使用过程中又是动态变化的，而课本一下子就提到一个叫滑动变阻器的装置，对学生来说，在变阻原理的理解上感到起点较高，对如何正确使用滑动变阻器学生更加感到难于接受。通过搭建一系列试验支架，降低探索难度，激发学生的学习兴趣，充分发挥学生的潜能，使他们的知识水平获得攀升，最大程度地提高了教学效率，取得了良好的教学效果。 二、构建案例情景(进入支架) 创设情境、进入情境、引入课 题 快递公司问题件快递公司问题件货款处理关于圆的周长面积重点题型关于解方程组的题及答案关于南海问题 (情景型支架) 演示:在黑板上方挂上彩灯，让彩灯由亮逐渐变暗、再由暗逐渐变亮，让学生观察思索其变化,思索其原因。目的是激发学生的学习兴趣与动机，引发探究的问题。教师引导:灯泡亮度的变化是由通过的电流引起的，我们知道，在电压不变的条件下，要改变电流只有改变电阻。那system troubleshooting. Integrated wiring system should have enough redundancy, can meet the development requirements. Rehabilitation Center backbone transmission using single-mode 12-core optical fibers, full reserve reserve to meet current and future period trunk signal transmission needs, rehabilitation center for future facility expansion needs. convenient and economical. Intranet and the Internet using a set of structured cabling systems. Medical treatment building, aerial parts of each layer on the rehabilitation floor weak current equipment set up between two 2 m network equipment cabinet, assigned to internal and external network devices. basement underground two-level shared network equipment rack. Medical treatment building intranet and extranet communication optical cable from the medical information room of the building leads, along the medical floor weak current tube into each layer individually weak current equipment. Recovery building intranet and extranet communication optical cable from medical and rehabilitation of ground floor one floor basement corridor into the rehabilitation floor weak current lines1th, floor and 2nd, floor of intranet and outside network of communications cable since medical integrated floor of information room leads, along rehabilitation center of weak tube respectively into 1th, floor of East, in the, West three seat floor a layer of weak equipment 么怎样改变连入电路的电阻呢,彩灯的电阻变化是由改变电阻的什么因素引起的, 三、学生探究(独立探索) (1)学生探究、理解原理(实验型支架) 实验探究:学生根据影响导体电阻大小的三个因素(导体的材料、横截面积和长度)去猜想。然后让学生选择桌面上的器材(铅笔芯、铜线、电炉丝、小灯泡、带夹子的导线、开关、电源等)，设计一个调节小灯泡亮暗的电路 方案 气瓶 现场处置方案 .pdf气瓶 现场处置方案 .doc见习基地管理方案.doc关于群访事件的化解方案建筑工地扬尘治理专项方案下载 ，并实际操作验证。 图1 方案一(改变导体的材料):如图1所示，在M、N间分别接入不同材的导体电阻，如铜丝和铅笔芯，观察小灯泡的亮度变化，观察并 记录 混凝土 养护记录下载土方回填监理旁站记录免费下载集备记录下载集备记录下载集备记录下载 小灯泡的亮度变化，并加以比较。 2a layer of weak equipmentfloor formation room leads, along rehabilitation center of weak tube respectively into 1th, floor of East, in the, West three seat t lines1th, floor and 2nd, floor of intranet and outside network of communications cable since medical integrated floor of incurrenoptical cable from medical and rehabilitation of ground floor one floor basement corridor into the rehabilitation floor weak weak current tube into each layer individually weak current equipment. Recovery building intranet and extranet communication dical information room of the building leads, along the medical floor level shared network equipment rack. Medical treatment building intranet and extranet communication optical cable from the me-ernal and external network devices. basement underground twoo intof each layer on the rehabilitation floor weak current equipment set up between two 2 m network equipment cabinet, assigned t conomical. Intranet and the Internet using a set of structured cabling systems. Medical treatment building, aerial partsenter for future facility expansion needs. convenient and ecore optical fibers, full reserve reserve to meet current and future period trunk signal transmission needs, rehabilitation c-mode 12-s. Rehabilitation Center backbone transmission using singlesystem troubleshooting. Integrated wiring system should have enough redundancy, can meet the development requirement 方案二(改变横截面积):如图1所示，在M、N间改变导线横截面积(分别接入1根笔芯与2根笔芯)，观察小灯泡的亮度变化，观察并记录小灯泡的亮度变化，并加以比较。 方案三(改变长度):如图1所示，在M、N间(有鄂鱼夹)夹入一段铅笔芯，使一端在铅笔芯上自由滑动，通过改变接入电路中铅笔芯的长度来改变接入电路中的电阻，观察并记录小灯泡的亮度变化，并加以比较。 交流评价1(协作学习1):让完成以上3种不同类型的小组相互交流，并归纳筛选出这样一个结果:改变导体的长度能较方便地改变小灯泡的亮度。最后师生共同总结归纳出:彩灯亮度的改变实质上是通过改变接入电路中导体的长度，来改变电阻，从而改变灯的亮度的。要想弄清其原理，我们先来学习一种能改变电阻的器件??变阻器。其实，根据上面的实验学生就已经悟出变阻器的工作原理。 (2)学生探究、学会使用(问题、实验型支架) 提出问题: 图2 第一个问题:要使灯泡和变阻器中的电流大小相同，变阻器应该与灯泡串联还是并联,(如图2) 第二个问题:滑动变阻器在使用过程中，你能不能知道它连入电路的阻值大小如何变化, integrated floor of information room leads, along rehabilitation center of weak tube respectively into 1th, floor of East, indical bilitation floor weak current lines1th, floor and 2nd, floor of intranet and outside network of communications cable since mextranet communication optical cable from medical and rehabilitation of ground floor one floor basement corridor into the rehaand e ds, along the medical floor weak current tube into each layer individually weak current equipment. Recovery building intranetal treatment building intranet and extranet communication optical cable from the medical information room of the building lealevel shared network equipment rack. Medic-ent cabinet, assigned to internal and external network devices. basement underground twobuilding, aerial parts of each layer on the rehabilitation floor weak current equipment set up between two 2 m network equipmtment sion needs. convenient and economical. Intranet and the Internet using a set of structured cabling systems. Medical treave reserve to meet current and future period trunk signal transmission needs, rehabilitation center for future facility expancore optical fibers, full reser-mode 12-habilitation Center backbone transmission using singlesystem troubleshooting. Integrated wiring system should have enough redundancy, can meet the development requirements. Re3the, West three seat floor a layer of weak equipment 实验探究:关于“滑动变阻器的使用方法”，我又为学生创设实验情境(如图3)，组织学生讨论滑动变阻器在使用过程中，它连入电路的阻值大小变化。 图3 接着分小组各自制定的计划进行操作，尝试改变灯泡的亮度。同时，教师巡视，并指导各实验小组将变阻器的实物连接、电路图连接、及电路符号连接进行对照，研究电阻变化的原理和规律。 交流评价2(协作学习2):各小组分别结合各自的实验结果相互讨论，交流比较改变灯亮暗的方法，共同归纳出: ? 能使变阻器电阻变化的接法有4种(“一上一下”); 图4 4a layer of weak equipmentfloor formation room leads, along rehabilitation center of weak tube respectively into 1th, floor of East, in the, West three seat t lines1th, floor and 2nd, floor of intranet and outside network of communications cable since medical integrated floor of incurrenoptical cable from medical and rehabilitation of ground floor one floor basement corridor into the rehabilitation floor weak weak current tube into each layer individually weak current equipment. Recovery building intranet and extranet communication dical information room of the building leads, along the medical floor level shared network equipment rack. Medical treatment building intranet and extranet communication optical cable from the me-ernal and external network devices. basement underground twoo intof each layer on the rehabilitation floor weak current equipment set up between two 2 m network equipment cabinet, assigned t conomical. Intranet and the Internet using a set of structured cabling systems. Medical treatment building, aerial partsenter for future facility expansion needs. convenient and ecore optical fibers, full reserve reserve to meet current and future period trunk signal transmission needs, rehabilitation c-mode 12-s. Rehabilitation Center backbone transmission using singlesystem troubleshooting. Integrated wiring system should have enough redundancy, can meet the development requirement ?不能使变阻器电阻变化的接法有2种，其中“同下”电阻总是很大，而“同上”电阻总是很小。 图5 本环节中重组了教材 内容 财务内部控制制度的内容财务内部控制制度的内容人员招聘与配置的内容项目成本控制的内容消防安全演练内容 ，让学生经历“提出问题??实验探究??交流评估”的探究过程，去主动突玻“变阻器”这一教学重难点，使学生“不仅知其然，而且知所以然。” 四、效果评价 运用支架教学理论，对以往的教学进行了大胆的改进，改进后的课堂教学具备以下优点:整堂课教学目标的制定与教学过程的展开紧密相连，教学过程的展开，由浅入深，由表及里，环环相扣，各个环节上创设了有利于学生学习的教学情境，设计了实现教学情境的必要手段或方法，为学生知识的建构搭建了合理的支架，降低探索难度，教师通过转变学生学习方式，不是将知识“灌输”给学生，而是以知识为载体，以全体学生的观察能力、探究能力和学生的合作能力为主要教学目标，将学生的能力发展为教学的主线，关注的是全体同学的共同发展。 本节课，通过搭建一系列支架，有力地突破了教学重点和难点，实现了三维一体的教育目标。 ds, along the medical floor weak current tube into each layer individually weak current equipment. Recovery building intranetal treatment building intranet and extranet communication optical cable from the medical information room of the building lealevel shared network equipment rack. Medic-ent cabinet, assigned to internal and external network devices. basement underground twobuilding, aerial parts of each layer on the rehabilitation floor weak current equipment set up between two 2 m network equipmtment sion needs. convenient and economical. Intranet and the Internet using a set of structured cabling systems. Medical treave reserve to meet current and future period trunk signal transmission needs, rehabilitation center for future facility expancore optical fibers, full reser-mode 12-habilitation Center backbone transmission using singlesystem troubleshooting. Integrated wiring system should have enough redundancy, can meet the development requirements. Re5the, West three seat floor a layer of weak equipment integrated floor of information room leads, along rehabilitation center of weak tube respectively into 1th, floor of East, indical bilitation floor weak current lines1th, floor and 2nd, floor of intranet and outside network of communications cable since mextranet communication optical cable from medical and rehabilitation of ground floor one floor basement corridor into the rehaand e