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1、Research into Cognitive Load Theory and Instructional Design at UNSWDr. Graham CooperUniversity of New South Wales, Australia(December 1998)Copyright 1998, Dr. Graham Cooper, School of Education Studies, The University of New South Wales, Sydney, NSW 2052, Australia.E-mail address: g.cooperunsw.edu.
2、au 1: Overview In recent years there has been an increased focus on the role of education and training, and on the effectiveness and efficiency of various instructional design strategies. Some of the most important breakthroughs in this regard have come from the discipline of Cognitive Science, whic
3、h deals with the mental processes of learning, memory and problem solving.Cognitive load theory (e.g. Sweller, 1988; 1994) is an instructional theory generated by this field of research. It describes learning structures in terms of an information processing system involving long term memory, which e
4、ffectively stores all of our knowledge and skills on a more-or-less permanent basis and working memory, which performs the intellectual tasks associated with consciousness. Information may only be stored in long term memory after first being attended to, and processed by, working memory. Working mem
5、ory, however, is extremely limited in both capacity and duration. These limitations will, under some conditions, impede learning.The fundamental tenet of cognitive load theory is that the quality of instructional design will be raised if greater consideration is given to the role and limitations, of
6、 working memory. Since its conception in the early 1980s, cognitive load theory has been used to develop several instructional strategies which have been demonstrated empirically to be superior to those used conventionally.This paper outlines some of the basic principles of cognitive load theory. Ex
7、amples of the instructional design strategies generated by cognitive load theory are also provided.2: Memory2.1 Remembering information Some people believe that we remember information by capturing it on something like a video tape in our minds. This is not the case. What we see and remember depends
8、 more on what we already know, than on what is actually presented.Look at each of the following, and note what you see.In the first example most people read THE CAT, even though the centre symbol in each word is the same. The context of reading provides information which we use to help interpret the
9、 symbols.In the second example most people will read each symbol as an example of the letter a, even though no two symbols are identical. We can read an infinite range of symbols as the letter a, even most peoples hand writing, although we have never seen their handwriting before. We are able to do
10、so because of our knowledge of what constitutes the letter a.Similarly, we are also able to recognise literally millions of different trees, as trees, even though no two are identical.These examples demonstrate that we cannot help but to impose meaning on things that we sense. Humans are able to beh
11、ave and think in intelligent ways because of their ability to quickly identify meaning in presented stimuli.Our knowledge and skills in activities as diverse as reading, driving, mathematics and gardening all derive from the knowledge base which we hold more-or-less permanently in long-term memory.2
12、.2 Chunking information When presented a large set of elements to remember, it is often helpful to combine the elements to form a smaller number of groups. Each of the groups is referred to as a chunk of information.For example, it is common practice to combine the digits of a phone number into two
13、or three chunks of several digits each, rather than listing all digits in one long sequence. The phone number 3476 - 2980 may be easier to remember than the sequence 3 4 7 6 2 9 8 0.Chunking does not need to be based upon any underlying meaning or logic that can be identified within the elements of
14、the to-be-learned information. However, if an underlying meaning or logic can be identified and is used to define the chunks, then remembering is greatly enhanced.For example, remembering a shopping list where elements are chunked into like groups, such as:is much easier to remember than a list of i
15、dentical elements which are chunked into groups without any underlying structure, such as:Look at each of the following statements in turn for just a few seconds, and try to memorise the sequence of letters and spaces.The first statement is difficult to memorise. The series of letters and spaces app
16、ears to be random. If we are unable to identify any form of pattern or meaning then we are reduced to a strategy of memorising individual letters in turn. If, however, we are able to identify the scrambled meaning, then our strategy for remembering becomes one of trying to remember the location of t
17、he spaces.The second statement is easy to memorise because the spaces are located in a way that promotes meaning. Consequently we need only memorise a few ideas (All fish, enjoy, clean water).When what we already know enables us to identify or impose meaning on a new piece of information because it
18、connects with information held in long-term memory, then it is relatively easy for us to remember it because we can build it into our existing knowledge base in a way that makes sense for us. The new information becomes an integral part of our overall knowledge, held in long-term memory.2.3 The moda
19、l model of memory It is now widely accepted that we have, and use, more than one type of memory.A modal model of memory distinguishes between three distinct memory types (modes). These are sensory memory, working memory and long term memory.Each mode has its own characteristics and limitations.These
20、 three modes are integrated to define an information processing model of human cognitive architecture.2.4 Sensory memory Sensory memory deals with incoming stimuli from our senses. These are sights, sounds, smells, tastes and touches. A separate partition of sensory memory exists for each of the sen
21、ses.Sensory memories extinguish extremely quickly. (About half a second for visual information, 3 seconds for auditory information). In that time, we must identify, classify and assign meaning to the new information or it will be gone forever.While looking at the picture below, quickly shut your eye
22、s, and keep them shut for a few seconds. Repeat this several times.As soon as you shut your eyes you may have noticed an image of the picture remaining for a split second somewhere in your mind. This demonstrates the operation of the partition of your sensory memory that deals with visual perception
23、s. This is not restricted to blinking at pictures. Look at anything around you and it will still work.2.5 Long term memory Long term memory refers to the immense body of knowledge and skills that we hold in a more-or-less permanently accessible form.Our name, date of birth, the letters of the alphab
24、et, how to read, how to write, how to drive, swim, play chess, catch a ball and everything else that we know is all held in our long term memory awaiting activation.Activation will occur as a direct result of our working memory querying long term memory for specific factual information (through our
25、consciousness). Once a query has been made activation (and the answer) is effectively instantaneous.Knowledge and skills that are activated with extremely high regularity, such as walking and talking, may be activated automatically without the need for high levels of conscious attention, even though
26、 the task itself may be a complex one. (Automation is discussed further in Section 3.3.)Consider each of the following questions.Question 1: What is your name?You will be able to answer this quickly. Its no surprise since it is referred to frequently and consists of only a few words. Note how quickl
27、y you can provide the answer.Question 2: What are the letters of the alphabet?Again, you will be able to answer this quickly but this is a more interesting question than the first. Here there are 26 items in the answer and virtually everyone presents the 26 items in the same order. Our long term mem
28、ory holds the letters of the alphabet in alphabetical sequence. If you try to say the letters of the alphabet in a random order, then you will find it an extremely difficult, probably impossible task.Question 3: Who won the lottery in 1992 at Wattle St., Sydney, Australia?Most people will quickly re
29、alise that they do not know the answer to this question. They recognise almost immediately that this is information that is not currently held in their long term memory. Generally, people know that they dont know.2.6 Working memory Working memory is the part of our mind that provides our consciousne
30、ss. It is the vehicle which enables us to think (both logically and creatively), to solve problems and to be expressive.Working memory is intimately related to where and how we direct our attention to think about something, or to process information.The biggest limitation of working memory is its ca
31、pacity to deal with no more than about seven elements of information simultaneously (Miller, 1956).Working memory capacity may be expanded slightly by mixing the senses used to present information. That is, it is easier to attend to a body of information when some of the information is presented vis
32、ually and the remainder of the information is presented auditorily than it is when all of the information is presented through a single sense (either all visually or all auditorily).If the capacity of working memory is exceeded while processing a body of information then some, if not all, of that in
33、formation will be lost.Consider answering both of the following questions without using pencil and paper.For most people Question 1 is quick and easy to solve as an example of mental arithmetic.In many ways Question 2 is nothing more than a larger version of Question 1, yet it is almost impossible t
34、o solve mentally.The role of long term memory is effectively the same for these two questions (to recall the rules of addition).The difference is that in Question 2 our working memory capacity is exceeded. It cannot cope with the large number of elements (in this case the numerals) that need to be a
35、ttended to simultaneously in order to solve this problem.The use of pen and paper aids solution to Question 2 because it effectively relieves the burden placed upon working memory by giving us a means of recording elements in a permanent form once we have finished processing them.3: Learning 3.1 Def
36、inition of learning Learning may be defined as the encoding (storage) of knowledge and/or skills into long term memory in such a way that the knowledge and skills may be recalled and applied at a later time on demand.Humans have a great capacity for learning and tend to spend their lives doing so. T
37、hey learn not only how to walk upright, but also how to talk, read and write. Many people today learn how to drive a car, operate a microwave oven, and use a computer. Some even learn how to perform a heart transplant operation. For all of these tasks (and just about every other task you care to men
38、tion) the role, capacity and qualities of sensory memory and working memory remain effectively unchanged. The driving force behind all skilled performance is the knowledge base that has been acquired within long term memory.The capacity of our long term memory to acquire knowledge appears to be unli
39、mited. No-one ever runs out of space, although with age there may be an overall deterioration in the performance of our memory system.It should also be noted that virtually everyone can learn how to drive a car, operate a microwave oven, use a computer or even perform a heart transplant operation, p
40、rovided that they are given sufficient time and training to enable them to acquire the necessary knowledge and skills.The next diagram presents part of an information network for cars for you to complete, or at least think about. There are no right or wrong answers.Spend a few minutes writing down i
41、n point form some information about cars. Some ideas have been included for you to work from but you are free to add anything you like. For example, details about their use, cost, construction, road rules, impact on the environment, history of development, principles of combustion engines, how to ch
42、ange gears, how to replace spark plugs.and so on.Work quickly, writing down ideas as soon as they come to you. If you spend more than a few seconds stuck, then begin another branch.Everyone living in modern society holds an enormous amount of knowledge regarding cars, their use, road rules, and so o
43、n. This knowledge base is held in a well structured information network which is itself connected to other networks. Networks such as those for transport or modern society are higher order concepts, while networks for seat belt, spark plugs and accelerator are lower order concepts. Knowledge about p
44、rocedures is also held (for example, how to park and how to change gears).These hierarchical information networks are referred to as schemas. Schemas build in detail and complexity as more extensive knowledge is acquired in a content area. The network in the diagram above is part of your schema for
45、cars held in your long-term memory.Individual differences exist in the nature and details of schemas. Someone who is employed as a mechanic and spends their pastime rebuilding vintage cars will have more detailed and complex schemas for cars than most people.Schemas that are well learnt may be recal
46、led and applied with relative ease. For example, someone learning to drive a manual car needs to concentrate intently on the knowledge and skills required to coordinate the movements of the clutch, gear stick and accelerator, in order to change gears smoothly. After several years of driving, however
47、, most people are able to change gears automatically. As automation develops, there is a reduction in the need for concentration.3.2 Process of learning The previous section (Section 3.1) argued that when we say that something has been learnt, we mean that is has been successfully encoded into long
48、term memory and can later be recalled on demand.The next question to be considered is how does information become encoded into long term memory? While the factors which contribute to encoding may vary from one situation to another, there is one factor that is always present. To be encoded, information must first be attended to, and processed by, working memory . If for any reason, working memory is unable to attend to a body of to-be-learnt information, then learni