漫谈教师教学发展中心课件.ppt

1、漫谈漫谈专长与认知师徒法专长与认知师徒法 华东师范大学心理与认知科学学院华东师范大学心理与认知科学学院 吴庆麟吴庆麟 2011 2011年年1010月月一、一、专长研究的启示专长研究的启示（一）专长研究的若干结论1 1、Experts Excel Mainly in Their own Domains.Experts Excel Mainly in Their own Domains.There is little evidence that a person highly skilled in one domain can transfer the skill to another.As M

2、insky and Papert(1974)noted:”a very intelligent person might be that way because of specific local features of his knowledge-organizing rather than because of global qualities of his thinking”(p.59).The obvious reason for the excellence of experts is that they have a good deal of domain knowledge.Th

3、is is easily demonstrated;for example,in medical diagnosis,expert physicians have more differentiations of common diseases into disease variants(Johnson et al.,1981).Likewise,in examining taxi drivers knowledge of routes,Chase(1983)found that expert drivers can generate a far greater number of secon

4、dary routes(i.e.,lesser known streets)than novice drivers.2.Experts perceive large meaningful patterns in 2.Experts perceive large meaningful patterns in their domaintheir domain.As mentioned,this is apparent in chess,where it is well known that chess masters excel in their recall of the clusters of

5、 pieces that they see.This perceptual superiority has been replicated in several other domains,such as in the game of GO(Reitman,1976),in reading circuit diagrams(Egan&Schwartz,1979),in reading architectural plans(Akin,1980),and in interpreting X-ray plates(Lesgold et al.,this volume).It should be p

6、ointed out,however,that this ability to see meaningful patterns does not reflect a generally superior perceptual ability;rather,it reflects an organization of the knowledge base.3.experts are fast;they are faster than novices at 3.experts are fast;they are faster than novices at performing the skill

7、s of their domain,and they performing the skills of their domain,and they quickly solve problems with little error.quickly solve problems with little error.An easy way to observe the skill of master chess players is to watch them play“lightning chess,”where they have only a few seconds to decide on

8、a move.There are at least two ways to explain experts speed.For simple tasks,such as typing,the speed that experts have acquired comes with many hours of practices,which makes the skill more automatic and frees up memory capacity for processing other aspects of the task(see Gentner,this volume).A fu

9、rther possible explanation for experts speed in solving problems rests on the idea emphasized earlier that experts can often arrive at a solution without conducting extensive search.The patterns that chess experts see on the board suggest reasonable moves directly,presumably because,through many hou

10、rs of playing,they have stored straightforward condition-action rules in which a specific pattern(the condition)will trigger a stereotypic sequence of moves.4.experts have superior short-term and long-term 4.experts have superior short-term and long-term memory.memory.With recently presented materia

11、ls,experts recall seems to exceed the limits of short-term memory.This is not because their short-term memory is larger than other humans,but because the automaticity of many portions of their skills frees up resources for greater storage.Experts seem to excel in long-term recall as well.For example

12、,in chess,it is not uncommon for chess masters to recognize plays from certain well-known games.5.experts see and represent a problem in their 5.experts see and represent a problem in their domain at a deeper(more principled)level than domain at a deeper(more principled)level than novices;novices te

13、nd to represent a problem at a novices;novices tend to represent a problem at a superficial level).superficial level).These results indicate that both experts and novices have conceptual categories,but that the experts categories are semantically or principle-based,whereas the categories of the novi

14、ces are syntactically or surface-feature oriented.6.experts spend a great deal of time analyzing a 6.experts spend a great deal of time analyzing a problem qualitatively.problem qualitatively.Protocols show that,at the beginning of a problem-solving episode,experts typically try to“understand”a prob

15、lem,whereas novices plunge immediately into attempting to apply equations and to solve for an unknown.What do the experts do when they qualitatively analyze a problem?Basically they build a mental representation from which they can infer relations that can define the situation,and they add constrain

16、ts to the problem.7.experts have strong self-monitoring skills7.experts have strong self-monitoring skills Experts seem to be more aware than novices of when they make errors,why they fail to comprehend,and when they need to check their solutions.(三)启示：知而获智,智达高远(二)当今知识分类观图解二、解读认知师徒法二、解读认知师徒法（一）问题的提出

17、（一）问题的提出 “仅是在上一个世纪的下半叶，仅是在一些工业化的社会中，正规的学校教育才成为教育年轻人的一种广为流行的方法，而在学校出现之前，师徒关系一直是一种最为通常的学习手段，并被用以作为传授某一实际专长领域所需知识的手段。”（二）两者的差异（二）两者的差异 “正规的学校教育与师徒法的差异是多方面的，不过，就我们的观念看来，其中一个最为关键的差异是，将学习之事委托给学校的一个副产品是，知识、技能已变得与他们在实际世界中的使用相分离，但在师徒法的学习中，我们要求学生所学的目标技能(target skills)，不仅为老道的参与者一直在使用，而且也成为实现有意义的学习任务的一种手段。换句话说，

18、师徒法将知识和技能的学习融于社会及功能的环境中。”（三）讨论的构架（三）讨论的构架实现学校学习与师徒法的整合认知师徒法的三种成功模式设计学习环境的一种框架三、解读三、解读“认知师徒法认知师徒法”“实现学校教育与师徒法的整合实现学校教育与师徒法的整合”（一）对当今学校教育弊端的讨论（一）对当今学校教育弊端的讨论 “尽管学校在组织以从传递大量的观念性与事实性知识体系方面是相对成功的，但通常以教学法则使专长中的一些关键方面变得为学生所看不见了。我们的教学通常很少关注专家在执行一些复杂的或现实的任务时所使用或获得知识的过程。即便在学校教学中也涉及到一些所谓的过程，但其关注的依然只是解决书本上的问题的一

19、些方法，或仅关注发展一些相对孤立的低级子技能，我们很少将自己的资源用于发展学生的更为高级的解决问题的活动，而正是这些活动要求学生对一些子技能和观念性知识作出积极的整合和适当的运用。“其结果是，在学校里所获得的一些观念性知识及解决问题的知识，对许多学生来说，依然是支离破碎的，或是死的知识(inert knowledge)”。“为了使学生的技能发生真正的差异，我们不仅要对实际专长的性质要有所了解，而且也要设计出与学习这些专长想适应的方法。为此，我们必须首先认识到，认知与元认知的策略与过程远比低级的子技能或抽象的观念性知识和事实性知识更为重要。”（二）传统的师徒法之关键：观察（二）传统的师徒法之关键

20、：观察（observationobservation）、）、指导（指导（coachingcoaching）、练习（）、练习（practicepractice）为了有助于读者了解传统的师徒法为何有效，Collins等人借助于Lave的研究文献提到了如下这些要点：1.1.这一方法历经的过程这一方法历经的过程 “首先师徒法密切关注执行某一领域任务的方法，而学徒学习这些方法则是通过Lave所说的观察、指导以及练习这些活动来学习这一方法的，按今天的话来说，便是通过示范（modeling），指（coaching）以及隐退（fading）来学习这些方法”。2 2、对这一过程若干环节的注解、对这一过程若干环节

21、的注解 “在这一活动顺序中，学生要反复观察(observation)师傅在执行或示范的目标过程，期间通常会涉及到要执行一些不同的，但又相互有联系的子技能。随后学徒尝试在师傅的指导和帮助下来执行这一过程（即所指的coaching），指导 的关键之处在于提供scaffolding（今译“支架”、“脚手架”或“支助”），即表现为教师给学生提供的提醒和帮助（即所谓的support），而学徒则在这些支持的帮助下，逐步实现能执行整个技能的合成。一旦学生掌握了总体技能，师徒便减少其参与，只给学生提供有限的提示或反馈(既所谓的fading），由此，让学生自己成功地、流畅地执行整个技能”。3 3、从传统的师徒向

22、认知师徒的转变、从传统的师徒向认知师徒的转变 鉴于80年代中期，一些研究人员在阅读、写作、教学等领域吸取了传统师徒法的一些做法，成功地开发了“合作学习”、“互惠教学”这些教学模式，Collins等人将这类教学方法统称为“认知师徒法”。理由一理由一：“这一方法主要是存在传统专家在处理复杂任务时所使用的过程。即认知师徒法强调观念性知识或事实性知识在解决问题或执行复杂任务中使用”。理由二：理由二：“我们采用认知师徒法这一术语旨在关注通过有指导的体验来学习认知与元认知过程，而非运动型的，体力性的过程。”理由三理由三：“认知师徒法还要求拓展鼓励学生发展自我纠正和自我监视的技能.(为此）我们确实了两种培养

23、这类至关重要的元认知技能的基本手段。其一是，通过专家和新手的角色互换，仅以概要性的角色扮演来对他们之间的差异作出反思,而鼓动发展自我监视与自我纠正技能的第二种方式是源于这一领悟：在执行复杂的技能时，需要问题解决者调整不同的认知活动.,因此，认知师徒法要求通过对话，讨论，师生角色的互换，集体的问题来实现这些技能的发展与内化。”4 4、两种师徒法的差异、两种师徒法的差异（1）传统的师徒法更关注的是工作作坊的需求或工作的需求，但是，这种从工作需求出发来选择学生所要练习的任务是一种最为无效的教学方式，而认知师徒法则强调任务的复杂性当逐步提升。“（2）传统的师徒法在经济上的考量既有利，但也会产生不太理想

24、的效果。（3）由于认知师徒法更关注知识使用的去情境化，因而它鼓励了对知识作出在不同情境中的使用。四、解读四、解读”认知师徒法认知师徒法“设计学习环境的一种框架设计学习环境的一种框架理想学习环境的特征理想学习环境的特征ContentDomain knowledgeHeuristics strategiesControl strategiesLearning strategiesModeling CoachingScaffolding and fadingArticulation Refection ExplorationMethods SequenceIncreasing complexityIncreasing diversityGlobal before local skillsSociology Situated learningCulture of expert practiceIntrinsic motivationExploiting cooperationExploiting competition