|
|
|
|
|
|
|
Bransford et al. (1990, 115) state that we "must help students learn to think for themselves and solve problems". They claim that this need has led educators to concentrate on the process of thinking rather than only on the content of thought, but they argue that knowledge of important content "knowledge of concepts, theories, and principles - empowers people to think effectively" and that without suitable knowledge, peoples' ability to think and solve problems is weak. This leads them to conclude that it is very important for educators to be able to teach important content in a way that facilitates thinking. Bransford et al. (1990, 116-123) talk about the problem of the frequent failure of students to transfer to new problem-solving situations. Among the many examples that they give is one about mathematics students at a college who are told that there are prizes to be gained for the solution of complex problems. The only restriction on them is that they cannot use calculators or computers. All these students had learned about logarithms, but despite this, none of them considered using them to solve the problems. Logarithms were seen as something that they did exercises on in their mathematics course and not as a tool for problem solving. There had been no transfer of knowledge to this new problem-solving situation. Bransford et al. claim that this knowledge that is not transferred is inert. The Cognition and Technology Group Learning Technology Centre at Vanderbilt University (1991, 34) (of which Bransford and his colleagues are members) state that the rationale for their recent work is the widespread concern about the perceived failure of society and the school system to help students to learn to think and to develop appropriate problem-solving skills. The Cognition and Technology Group at Vanderbilt (1991, 34) state that: Many argue that a major cause of poor performance on tasks that require the generation of relevant sub-problems, arguments, and explanations is that most curricula emphasise the memorisation of facts and the acquisition of relatively isolated sub-skills that are learned out-of-context and hence result in knowledge representations that tend to remain inert. Alternatives to fact memorisation and out-of-context practice include an emphasis on in-context learning that is constructive or generative in nature and is organised around authentic tasks that often involve group discussion. Jonassen (1991, 36) illustrates this situation by stating that his own fifth grade daughter is currently: struggling to memorise names and facts about sub-phyla of animals that she has never seen, nor likely ever will. The information is dictated to her. Her obligation is to memorise and regurgitate it. She will forget it almost immediately, because she has no personal need to know it in the first place. Jonassen (1991, 36) claims that the "most common instructional sin of educators and designers (and therefore of the most practical and palpable relevance to designers) is that of decontextualising learning". He states that many constructivist cognitive theories of learning state that decontextualised learning is less meaningful and, therefore, less memorable and that constructivists claim that "context-free learning is a hollow, irrelevant experience". Information is best learned through the context of some real-world problem or experience and the most effective contexts are problem or case based activities which "immerse the learner in the situation requiring him or her to acquire skills or knowledge in order to solve the problem or manipulate the situation" (Jonassen 1991, 36). He notes, however, that much of the information presented in schools is taken out of context and is presented as truth or reality. This results in our youth being "daily subjected to acquiring countless facts and rules that have no importance, relevance, or meaning to them because they are not related to anything the learners are interested in or need to know" (Jonassen 1991, 36). Jonassen describes a number of constructivist approaches to instruction that attempt to contextualise information: ... anchored instruction emphasises anchoring instruction in a relevant macro-context that is perceptually rich and realistic as possible. Immersion in the environment stimulates generative learning of meaningful knowledge. Flexibility theory emphasises the provision of a variety of contexts for instruction in order to represent the multiple perspectives or interpretations of the same ideas. There is no universally accepted reality, so designers should try to represent the multiple perspectives that comprise a constructed reality. Other cognitive models ... such as situated cognition, argue that instruction should include authentic, relevant tasks that focus on everyday cognition. It is Anchored Instruction that the the Cognition and Technology Group at Vanderbilt is currently researching. Bransford et al. describe it in the following terms: The model is designed to help students develop useful knowledge rather than inert knowledge. At the heart of the model is an emphasis on the importance of creating an anchor or focus that generates interest and enables students to identify and define problems and to pay attention to their own perception and comprehension of these problems. They can then be introduced to information that is relevant to their anchored perceptions. The major goal of anchored instruction is to enable students to notice critical features or problem situation and to experience the changes in their perception and understanding of the anchor as they view the situation from new points of view (1990, 123). Anchored instruction starts with a "focal event or problem situation that provides an anchor for students' perceptions and comprehensions". This anchor will be interesting and will enable students to deal with a general goal that involve a series of related sub-problems or sub-goals. The anchor should emphasise various features of the problem that make subsequent actions relevant (Bransford et al. 1990, 123). Case-based approaches are one example of anchored instruction. In this, the students are first presented with a case which contains a variety of problems which have to be solved. As the students are introduced to new concepts, they see the result of this new knowledge on the problems that they confront. In such cases, the information is normally presented verbally. While this is often a suitable medium, Bransford et al. claim that there are also advantages in providing video-based anchors (1990, 124). One advantage of video-based material is that it is a much more information rich medium than printed media. "Gestures, affective states, scenes of towns, music and so on always accompany the dialogue". Because there is more to notice, there is an increased opportunity to identify relevant information in the video sequence. This "provides an opportunity to encourage problem finding and problem representation rather than to always provide preset problems to students". It also provides an opportunity to demonstrate to students how their perceptions and comprehension change as they view the material from different points of view (Bransford et al. 1990, 124). A second advantage of using video-based materials is, according to Bransford et al. (1990, 124), that "the ability to perceive dynamic, moving events facilitates comprehension". They suggest that young children may need to see waves and strong winds in order to appreciate the concepts, while other students may need to see video material showing acceleration and constant velocity in order to appreciate the difference. They support this view by describing the work of Johnson (1987) with two groups of children, the first of which was instructed verbally while the second used information from a videodisc. He found that "The video-based instruction resulted in much greater retelling scores and comprehension scores than did the instruction that was conducted in verbal form". A third advantage of using video-based material described by Bransford et al. (1990, 125) is the importance of "conditioning one's knowledge". They cite Simon (1980) as arguing that: the knowledge representation underlying competent performance in any domain is not based on simple facts or verbal propositions but is instead based on productions. Productions involve "condition-action pairs that specify that if a certain state occurs ..., then particular mental (and possibly physical) actions should take place" (Anderson 1987, 193, cited in Bransford et al. 1990, 120). These productions give information about critical features of a problem-solving situations that make specific actions relevant. The acquisition of knowledge in these condition-action pairs which are mediated by goal oriented hierarchies instead of being in the form of isolated facts is termed 'conditionalising' knowledge (Bransford 1990, 120). Bransford et al. (1990, 125) maintain that "Without knowledge of the appropriate 'triggering conditions', relevant knowledge will not be accessed and applied". They cite Simon (1980) as stating that: ... often, our educational system fail to develop the pattern recognition abilities necessary to specify the condition side of condition action pairings. It is often difficult to develop skills of pattern recognition when one teaches in a primarily verbal mode. As has been stated, the source of video material for the work conducted by the Cognition and Technology Group at Vanderbilt was videodisc. Unfortunately, videodiscs are expensive to produce. Cohen (1990, 35) reports that a group at San Jose State University received a grant of $35,859 to put 8,000 images on to videodisk, a process which would not have required any high level of programming, which is expensive. This can be compared with the cost of an "interactive videodisc project, with high production values for a general audience, [which] might typically cost about $250,000" (Hoekema 1992, 28). The situation in the United States in regard to videodisc, is somewhat different to that in Australia. In the US, commercial videodiscs are freely available at a reasonable price and various films are distributed on them. Researchers at Vanderbilt and elsewhere have been using these commercially produced videodiscs in their work. Bransford et al. (1990, 129-130) used commercial videodiscs for a variety of research projects one of which investigated anchors for science instruction. This project used the first ten minutes of the Raiders of the Lost Ark. It was divided into 13 short passages on topics that might be encountered in middle and high school science classes. Examples given were:
The results obtained indicated that students who had received information in a problem-solving context were much more likely to remember it and to spontaneously use it in new situations than those who had received it in a non-problem-solving context. Bransford et al. (1990, 132) also describe success in getting students to produce their own computer-videodisc presentations using segments from commercially available videodiscs. They give an example of a group of students working on the topic of light who used segments from Star Wars to illustrate some important concepts about light. They conclude that: Although this fact could be read in a science text book, the use of a very short video segment, tied with text, appears to make the learning of this type of information more meaningful and interesting for the students who produced the video and for the other students who watch the production. The Cognition and Technology Group at Vanderbilt (1991, 35-36) describe a series of videodisc-based, mathematics presentations called The Jasper Series which they produced. Unlike the material described by Bransford et al., these videodiscs were prepared especially for this project. The group describe the seven basic design principles that they used in the Jasper series as follows: 1. Video-based presentation. The reasons that they gave for using video-based presentations as opposed to using oral or written media included the following:
2. Narrative format The reasons for presenting the material in a story format were given as:
3. Generative learning format All the stories (apart from one) are complete and include information about the setting and a slate of characters. They have an initiating event and a series of consequent events. The main difference between these and normal stories is that the resolution must be provided by the students (the resolution is on the disc, but students only gain access to it after they have proposed their own). To reach their resolution, student must generate and resolve a series of complex mathematical problems. The reasons for using this design are:
4. Embedded data design All the data that is required to solve the problems is embedded in the video. The problems are not explicitly described and data is presented incidentally. It is claimed that this is an extremely important design feature which is unique to this series. It is instrumental in allowing students to engage in generative problem solving. Students look back on the video to find the data that they require and it is claimed that this is motivating. This embedded data makes the series like a good mystery thriller where, upon finishing it, the reader can see that all the clues were presented during the story although it was not obvious at the time of reading. 5. Problem complexity The stories pose very complex mathematical problems. In the first episode, for example, the problem comprised more than 15 interrelated steps and in the second one, multiple solutions have to be considered in order to identify the optimal one. The complexity of the problems is intentional and uses a very simple premise; "Students cannot be expected to learn to deal with complexity unless they have the opportunity to do so". Students in schools are not often given the chance to engage in complex problem-solving. One reason for this, it is believed, is that teachers find it difficult to present all the information required for complex problem solving while maintaining the motivation and interest of the students. Video, however, makes complexity manageable. 6. Pairs of related adventures All of the stories were prepared in pairs. This was done to increase the chance of transfer . Concepts that are acquired in only one context tend to be welded to it and so they are not likely to be accessed and used in a new situation. From an analysis of the two videos, students can see which problem-solving strategies, for example, are relevant to only one situation and which ones are generalisable. 7. Links across the curriculum The narrative contains opportunities to form links with other curriculum areas. The Cognition and Technology Group at Vanderbilt (1991, 37) describe the Jasper series in the following way: Each video is a complete story and is between 17 to 20 minutes in length. At the end of each video, a character from it states the problem which is posed as a challenge and the students have to generate relevant sub-problems in order to achieve the solution. All the necessary data is included in the video and the problem that is posed is complex. Each pair of videos contain similar problems, for example, both videos that comprise the first pair deal with planning a trip while those in the second pair deal with establishing a business plan. There is the potential to create links which move from mathematics to other subject areas. The first episode of the pair of trip-planning videos is entitled Journey to Cedar Creek. This episode opens with Jasper Woodbury practicing his golf swing. The newspaper is delivered and Jasper turns to the classified ads for boats. Jasper sees an ad for a 1956 Chris Craft cruiser and decides to take a trip to Cedar Creek where it is docked. He rides his bicycle to the dock where his small "row" boat, complete with outboard motor, is docked. We see Jasper as he prepares for the trip from his dock to Cedar Creek: He is shown consulting a map of the river route from his home dock to the dock at Cedar Creek, listening to reports of weather conditions on his marine radio, and checking the gas for his outboard. As the story continues, Jasper stops for gas at Larry's dock. Larry is a comical-looking character who knows lots of interesting information. For example, as he hands Jasper the hose to the gas pump, he just happens to mention all the major locations where oil is found. When Jasper pays for the gas, we discover the only cash he has is a $20 bill. As Jasper makes his way up the river, he passes a paddle-wheeleer, a barge, and a tugboat, and some information is provided about each of these. Next, Jasper runs into a bit of trouble when he hits something in the river and breaks his shear pin. He has to row to a repair shop where he pays to have the pin fixed. Later, Jasper reaches the dock where the cruiser is located and meets Sal, the cruiser's owner. She tells him about the cruiser and they take the boat out for a spin. Along the way, Jasper learns about its cruising speed, fuel consumption, and fuel capacity, and that the cruiser's temporary tank holds only 12 gallons. He also learns that the boat's running lights don't work, so the boat can't be out on the river after sunset. Jasper eventually decides to buy the old cruiser, and pays with a check (sic). He then thinks about whether he can get to his home dock by sunset. The episode ends by turning the problem over to the students to solve. After viewing the video, students move to an "active generation mode" in order to solve Jasper's problem. Students must generate the same type as problem that Jasper must take into account when making his decision about whether or not he can get the boat home by dark. This process involves the generation of a variety of sub-problems. The students have to search the video to obtain the information that they require. For example, to determine how far Jasper has to travel, the students have to view a map that Jasper consulted at the start of the video, and to find out what time the sun sets, they have to listen to the messages on the marine radio. |
|
|
|
|
Conclusions |
|
|
Anchored instruction would appear to be a very suitable constructivist design strategy for preparing computer based instruction materials for the teaching of content-dependent subjects such as science. Its approach appears to be logical and it is backed up by a considerable amount of work and is supported by research. There would, however, appear to be limitations to its practical application in the classroom. These limitations stem from the medium used for storing the video sequences. While it would be possible to access the video from tape, a great deal of the flexibility of the system would be lost as the searching which is required would have to be conducted in a linear fashion and would be time consuming. Videodisc stores data in individual frames and there are 54,000 of these to hold 30 minutes of video on each side of the disc. This allows the video to be viewed at the normal rate, in slow motion or even freeze frame. In addition, as each frame is addresses, it can be accessed directly. The videodisc can be controlled by a hand-held device, or by a computer. If a computer is in control, control programs can be produced which will automatically access different parts of the disc and even play non-contiguous segments as a sequence (Bransford et al. 1990, 125). The problem with videodisc as the storage medium is that, as has been stated, commercially produced videodiscs are not freely available in Australia and the production of non-commercial discs is expensive. The work conducted by Bransford et al. involved the use of commercially produced videodiscs. While their use as a research tool is valid, it could be argued that their use within the education system, where there is normally a prescriptive curriculum which must be adhered to, could produce major management problems as the material to be covered by an instructional session would be dictated by the content of the videodisc rather than the curriculum requirements. While the videodiscs in the Jasper series are custom made and so would comply much closer to the curriculum requirements, as so many aspects of the curriculum are covered within each story, if they were to be used on a large scale, management problems could also arise. It would also appear to be a difficult task to create stories which would cover all aspects of the curriculum. Presumably, however, the argument against these objections is that the videodiscs are designed for teaching problem-solving techniques rather than specific content. While this may be valid, it does not assist in the teaching of specific content in a constructivist manner. A way of overcoming these objections could be to use the computer directly as the video source for the instructional sequences. Recently, Apple Computers have made great progress with the integration of computers and video. QuickTime, an extension of the Macintosh operating system, allows the integration of time dependent applications such as video, animation and sound into a variety of other applications. In practical terms, this means that real time video can be played from within a HyperCard stack. The QuickTime and associated software, allows video to be captured into a file, compressed so as to reduce the storage overheads, and manipulated to form new 'movies'. Such video can be moved from movie to movie using the cut and paste metaphore familiar to all users of Macintosh word processing programs. Using additional software, special effects can be incorporated and sound tracks added. Single frames can also be captured from the live video. While video compression can be used, the movie files can still become large with several megabytes being required to store 1 minute of video 2. In view of this, CD-ROM becomes the storage medium of choice. While both CD-ROM and videodiscs are optical discs, the price of mastering a CD-ROM ($350) is much cheaper than mastering a videodisc. It is suggested that, using QuickTime, small video sequences on specific topics could be used as anchors in science HyperCard-based CBI materials. It has already been stated that students search the videodisk to find relevant information after the initial viewing. If a HyperCard stack was used, the relevant information that students might require could be placed on separate cards as either small movies or individual frames taken from the movie. Additional information could be Embedded in to these graphics, e.g. text which is displayed when a part of the graphic is 'clicked'. In addition, other associated information could be included in the stack using a variety of media. The only problem seen with this situation, at this stage, is the method of information retrieval by students. The students should be able to decide what information they want to access and should not be guided. If an index was produced, it would act as a guide to the students. It would appear that some natural language interface would have to be developed so that the student could type "Show me the boat" and a picture of the boat would be displayed. The advantages of this QuickTime-based anchord instruction as opposed to videodisc-based materials are seen as being: The instructional materials would be a lot cheaper to produce. The materials could be used on normal classroom computers whereas there would normally be access to only 1 videodisk player in a school. If CD-ROM was used as the storage media, the player could be networked to a number of computers.
Disadvantages are seen as being:
|
|
    |
|
|
Author: Tony Brown Created: 25.6.97 © The University of New England, NSW, Australia |
