[Date: September 2, 2005] Source: Central Audio-visual Education Center Author: [Font: large, medium and small]
First, the significance of multimedia education applications
Since 1990s, multimedia technology has risen rapidly and flourished. Its application has spread all over the national economy and social life, and it is bringing great changes to human production mode, working mode and even lifestyle. Especially because multimedia has the characteristics of pictures, words, sounds and even moving images, it can provide the most ideal teaching environment and will inevitably have a far-reaching impact on the education and teaching process. This profound influence can be summarized in one sentence: multimedia technology will change teaching mode, teaching content, teaching means and teaching methods, and eventually lead to fundamental changes in the whole educational thought, teaching theory and even education system. The reason why multimedia technology is so important to the field of education is that multimedia technology itself has many characteristics and functions that are particularly valuable to the education and teaching process. These features and functions are not available or fully available in other media (such as slides, projection, movies, audio recording, video recording, television, etc.). ). First of all, the multimedia technology mentioned here is computer-centered multimedia technology. In some books in previous years, multimedia combination teaching was mentioned. The concept of multimedia is different. It is just a simple combination of several media (for example, a combination of slides, projections, audio and video). Today's multimedia technology is computer-centered, integrating voice processing technology, image processing technology and audio-visual technology, and converting voice signals and image signals into unified digital signals through analog-to-digital conversion. After that, the computer can conveniently store, process, control, edit and convert them, and can also query and retrieve them. Obviously, this is completely different from the original combination of various media forms, because it integrates several technologies to process different media information through computers. The integration method is to convert everything into digital through analog-to-digital conversion; Moreover, in order to facilitate processing and transmission, it is necessary to compress the data, transmit it to the designated place and then restore it. There is a set of complex technologies realized by computers. So today's multimedia technology is actually embodied by multimedia computers. I will explain the great significance of multimedia computer to educational application from four aspects: its characteristics and functions.
1, the interactivity of multimedia computers is beneficial to stimulate students' interest in learning and play the role of cognitive subject.
Human-computer interaction and instant feedback are the remarkable characteristics of computers, which are not available in any other media. Multimedia computer further combines the audio-visual fusion function of TV with the interactive function of computer, resulting in a new and colorful man-machine interaction mode with pictures and texts, and can give immediate feedback. This interactive way is of great significance to the teaching process, which can effectively stimulate students' interest in learning and make them have a strong desire to learn, thus forming learning motivation. Interaction is unique to computers and multimedia computers. It is precisely because of this feature that multimedia computer is not only a teaching method, but also an important factor to change the traditional teaching mode and even teaching thought.
As we all know, in the traditional teaching process, everything is decided by the teacher. The teaching content, teaching strategies, teaching methods, teaching steps and even the exercises that students do are all arranged by the teacher in advance, and students can only passively participate in this process, that is, they are in the state of being indoctrinated. In the interactive learning environment such as multimedia computer, students can choose what they want to learn according to their own learning foundation and interests, and they can choose exercises suitable for their own level. If the teaching software is well compiled, you can even choose the teaching mode, such as individualized teaching mode or consultation and discussion mode. Let the computer discuss and communicate with you like a study partner. In other words, students have the possibility of active participation in such an interactive learning environment, instead of being arranged by teachers, students can only passively accept it. According to the cognitive learning theory, human cognition is not directly endowed by external stimuli, but produced by the interaction between external stimuli and human internal psychological processes. Only by giving full play to students' initiative and enthusiasm can we get effective cognition. This kind of active participation creates good conditions for students' initiative and enthusiasm, that is, it can truly reflect students' cognitive role.
2. The diversity of external stimuli provided by multimedia computers is conducive to the acquisition and maintenance of knowledge.
The external stimulus provided by multimedia computer is not a single stimulus, but a comprehensive stimulus of multiple senses. This is very important for the acquisition and maintenance of knowledge. Experimental psychologist Treicher has done two famous psychological experiments. One is about the source of human information, that is, the main way for human beings to obtain information. He confirmed through a large number of experiments that 83% of the information obtained by human beings comes from vision, and 1 1% comes from hearing, which adds up to 94%. The other 3.5% comes from smell, 1.5% comes from touch, and 1% comes from taste. Multimedia technology can be seen, heard and operated by hand. In this way, the amount of information obtained through various sensory stimuli is much stronger than that obtained by simply listening to the teacher's lecture. Information and knowledge are closely related, and you can master a lot of knowledge by obtaining a lot of information. He also did another experiment, which was about knowledge retention, that is, the persistence of memory. The result is this: people can generally remember 65,438+00% of what they read, 20% of what they heard, 30% of what they saw, 50% of what they heard and saw, and 70% of what they communicated. In other words, if you can hear and see, and then express it in your own language through discussion, the maintenance of knowledge will be much better than that of traditional teaching. This shows that the application of multimedia computer in the teaching process is not only very conducive to the acquisition of knowledge, but also very conducive to the maintenance of knowledge.
3. Hypertext function can realize the most effective organization and management of teaching information.
Hypertext is an advanced technology to organize and manage information nonlinearly according to the associative thinking mode of human brain. If the information managed is not only words, but also graphics, images, sounds and other media information, it becomes a hypermedia system, in other words, hypermedia is multimedia plus hypertext. In fact, most multimedia systems use hypertext to organize and manage information. Therefore, generally speaking, we can also regard hypertext as a unique function of multimedia system without distinguishing between hypermedia system and multimedia system.
If a book is organized in hypertext, it is completely different from traditional documents or printed books. At this time, texts (articles, paragraphs or sentences or words) are organized into text networks according to their interrelationships. This book doesn't care about the first page or the last page. Which paragraph to start reading and what to read next are the readers' own wishes. The basis for selecting the next paragraph of text is not the order or index, but the semantic connection between texts. The research of cognitive psychology shows that human thinking has associative characteristics. In the process of reading or thinking, people often move from one concept or topic to another related concept or topic because of association. Therefore, the nonlinear and networked way of organizing management information in hypertext is more in line with people's thinking characteristics and reading habits than the linear and orderly way of traditional text.
Hypertext has the above advantages because of its structural characteristics. The basic structure of hypertext consists of nodes and links. Nodes are used to store all kinds of information. The content of nodes can be text, sound, graphics, images or a moving image. The node size can be a window, or the data contained in a frame or several frames, and the association between nodes (that is, various information) is represented by chains. There are many different types of nodes and chains, thus forming various multimedia systems.
Using the hypertext function of multimedia to realize the organization and management of teaching information has the following advantages:
(1) According to the requirements of teaching objectives, various teaching contents containing different media information can be integrated into an organic whole. In the traditional printed teaching materials, the contents of sound and moving images can not be integrated with the written content, and can only be published separately in the form of textbooks, audio tapes and video tapes. Obviously, the content of such textbooks must be monotonous and boring, which is different from the illustrated and colorful electronic textbooks organized by hypertext.
(2) According to the requirements of teaching content, integrate all kinds of teaching materials with different teaching requirements. Each teaching unit in the teaching process includes texts, exercises, exercises, questions, tests, test answers and corresponding demonstrations or experiments. It is undoubtedly beneficial to arrange these teaching materials with related teaching contents and different teaching requirements in class, after-class review or self-study. However, it is impossible to organize and manage teaching contents according to traditional texts.
(3) According to the students' knowledge base and level, the preparatory knowledge of related disciplines and the supplementary knowledge needed to broaden their horizons can form an organic whole. Teaching students in accordance with their aptitude is one of the important goals to optimize the teaching process. However, due to the great differences among students, traditional printed textbooks can't meet the different needs of poor students, ordinary students and excellent students for teaching content, but it is easy to set hotkeys related to preparatory knowledge and supplementary knowledge in multimedia electronic textbooks.
4. Multimedia computer can be used as a cognitive tool to realize an ideal learning environment.
From the mid-1980s to the early 1990s, computers were widely used in the field of education in two aspects: first, as a data processing tool (such as the application of various databases and spreadsheet processing software); Second, as a WORD processing tool (such as WPS and Word software). In recent years, computer, as a tool, has made great progress in the field of education. It is an effective cognitive tool in the teaching process.
As we all know, in the past 20 years, behaviorism learning theory, which emphasizes stimulus-response and regards learners as passive response to external stimuli, that is, the object of knowledge infusion, has given way to cognitive learning theory, which emphasizes the internal psychological process of cognitive subjects and regards learners as the subject of information processing. With the deepening of psychologists' research on the cognitive law of human learning process, constructivism learning theory, an important branch of cognitive learning theory, has gradually become popular in the West. Due to the various characteristics of multimedia computer and network communication technology, it is especially suitable for realizing constructivist learning environment. In other words, multimedia computer and network communication technology can be used as ideal cognitive tools in the constructivist learning environment, which can effectively promote students' cognitive development. Therefore, with the rapid development of multimedia computers and the Internet, constructivist learning theory is increasingly showing its strong vitality and expanding its influence in the world.
Next, we will briefly expound the basic content of constructivism learning theory from two aspects: the meaning of learning (that is, what is learning) and the method of learning (that is, how to learn).
(1), the meaning of learning
Learning is the process of acquiring knowledge. Constructivism holds that knowledge is not acquired by teachers, but by learners in a certain situation, that is, social and cultural background, with the help of others (including teachers and learning partners), using necessary learning materials and through the way of meaning construction. Because learning is a process of meaning construction under a certain situation, that is, social and cultural background, with the help of others, that is, through interpersonal cooperation activities, constructivism learning theory holds that "situation", "cooperation", "conversation" and "meaning construction" are the four major elements or attributes in the learning environment.
"Situation": The situation in the learning environment must be conducive to students' construction of the meaning of what they have learned. This puts forward new requirements for instructional design, that is to say, in the constructivist learning environment, instructional design should not only consider the analysis of teaching objectives, the analysis of learners' characteristics and the selection and utilization of media, but also consider the creation of scenarios that are beneficial to students' constructive meaning, and take the creation of scenarios as one of the most important contents of instructional design.
"Collaboration": Collaboration occurs in the whole learning process. Collaboration plays an important role in the collection and analysis of learning materials, the proposition and verification of hypotheses, the evaluation of learning achievements and the final construction of meaning.
"Conversation": Conversation is an indispensable link in the process of collaboration. The members of the study group must discuss how to complete the prescribed study task plan through conversation; In addition, the process of collaborative learning is also a dialogue process, in which each learner's thinking achievement (wisdom) is shared by the whole learning group, so dialogue is one of the important means to realize meaning construction.
"Meaning construction": This is the ultimate goal of the whole learning process. The meaning to be constructed refers to the essence, laws and internal relations of things. Helping students to construct meaning in the process of learning is to help students reach a deeper understanding of the nature and laws of things reflected in the current learning content and the internal relationship between this thing and other things. The long-term storage form of this understanding in the brain is the cognitive structure of what is currently learned, which is also called "schema".
(2) About learning methods
Constructivism advocates learner-centered learning under the guidance of teachers, that is to say, it not only emphasizes the cognitive subject role of learners, but also does not ignore the leading role of teachers. Teachers are helpers and promoters of meaning construction, not providers and instigators of knowledge. Students are the main body of information processing and the active constructors of meaning, not the passive recipients and indoctrinated people of knowledge.
Students should become active constructors of meaning, which requires students to play the main role in the learning process from the following aspects:
(1) To construct the meaning of knowledge by exploration and discovery;
In the process of constructing meaning, students are required to actively collect and analyze relevant data and materials, and put forward various assumptions about the problems they have learned and verify them;
(3) Ask students to try to connect the content reflected in the current learning content with what they already know, and seriously think about this connection. "Contact" and "thinking" are the keys to meaning construction. If we can combine the process of contact and thinking with the process of negotiation (that is, the process of communication and discussion) in collaborative learning, the efficiency and quality of students' meaning construction will be higher. There are two kinds of negotiation: self-negotiation and communication negotiation (also called internal negotiation and social negotiation). Self-negotiation refers to arguing with yourself about what is right. Communicative negotiation refers to the discussion and debate between study groups.
Teachers should become helpers in the construction of students' meaning, which requires teachers to play a leading role in the teaching process from the following aspects:
① Stimulate students' interest in learning and help them form learning motivation;
(2) Help students to construct the meaning of what they have learned by creating scenes that meet the requirements of teaching content and clues to connect old and new knowledge.
(3) In order to make meaning construction more effective, teachers should organize collaborative learning (discussion and communication) under possible conditions, and guide the process of collaborative learning to make it develop in a direction conducive to meaning construction. The methods of guidance include: raising appropriate questions to arouse students' thinking and discussion; Try to guide the questions step by step in the discussion to deepen students' understanding of what they have learned; It is necessary to inspire and induce students to discover the law themselves, correct and supplement their wrong or one-sided understanding, and avoid instilling it directly into students.
Let's explain how to use multimedia computer and network communication technology as cognitive tools to realize such a learning environment through two practical classes.
Lesson 1: Experiment of "Muniburns Central Primary School" in Australia
The experimental class is Grade Six, with 30 students. The teacher's name is Andrea, and the current teaching content is about the Olympic Games. As usual, Andrea encourages her students to formulate some topics around the teaching content (such as the history of the Olympic Games and Australia's achievements in previous Olympic Games), and determines the role of the media in solving these problems, requiring students to express their chosen problems intuitively and vividly in the form of multimedia. After consulting materials in the library and the Internet for a period of time, two children, Machelle and Sarah, made a multimedia presentation software about the history of the Olympic Games. Before playing the software to the whole class, the teacher reminded everyone to observe and analyze the content and characteristics of the software. Discuss it immediately after the broadcast. A student said that from the time axis of the Olympic Games, he noticed that the Olympic Games are held every four years. Another student put forward a different view. He believes that this is not always the case. For example, 1904, 1906 and 1908 are held every two years. Some students noticed that the Olympic Games were not held in the years of 19 16, 1940 and 1944 on the time axis. At this time, the teacher asked, "Why didn't you hold the Olympic Games these years?" Some students replied that some important events happened in these years, some students replied that there was a war, and some students pointed out more accurately that 19 16 was closed because of World War I, while 1940 and 1944 were closed because of World War II. After discussion and consultation, we decided to make two supplements to the multimedia software developed by Michele and Sarah: ① to explain the influence of World War I and World War II on hosting the Olympic Games; (2) Give a special explanation to several transitional (biennial) Olympic Games in the early Olympic history. At this time, a child suggested that Hitler's photo be scanned to the point of 1940 on the time axis, indicating that he launched World War II. The teacher asked the rest of the class, "Do you have any different opinions?" Sarah raised her hand and answered loudly, "I don't agree to use Hitler's photo." We should use a photo that can truly reflect the great disasters brought to the people by World War II (such as mass bombing or mass slaughter of Jews) to arouse people's hatred of Hitler. " The teacher praised Sarah's speech.
As can be seen from the above example, the teaching design for this teaching unit is mainly to let students use multimedia computers to build a scene about a special topic of the Olympic Games (such as the history of the Olympic Games or Australia's achievements in previous Olympic Games), so as to stimulate students' interest in learning and take the initiative to explore, and then gradually guide a deeper understanding of relevant teaching content through discussion. In this class, students are always in the cognitive subject position of active exploration, active thinking and active construction of meaning, but it is inseparable from the teacher's careful teaching design in advance and the guidance in the process of collaborative learning. Teachers say little in the whole teaching process, but it is of great help to students in constructing meaning, which fully embodies the combination of teachers' leading role and students' main role. The whole teaching process revolves around the cognitive links of constructivism, such as scene, cooperation, dialogue, meaning construction, etc., and it is carried out in the multimedia computer environment from beginning to end (and information query is realized by using the Internet at the same time), so the above example is a good example of realizing a constructivist learning environment with multimedia computers and the Internet as cognitive tools.
Lesson Two: The Experiment of Wei Zhi Burke Primary School in Australia.
The experimental class consists of students in grade three and grade four. The teacher in charge of the experiment is Mary, and the teaching content in the science class is animals. Mary's teaching design of this teaching unit is mainly to let students design an electronic tour guide about the local zoo with multimedia computers, so as to establish a scene conducive to the construction of the concept of "animals". Mary thinks this situation is very attractive to students, so it can effectively stimulate their interest in learning. She divided the experimental class into several groups, and each group was responsible for developing a multimedia demonstration of the pavilion in the zoo. Mary let the children choose for themselves: which exhibition hall they want to develop and which animal they want to choose; Would you like to collect relevant animal pictures or write corresponding text descriptions for the pictures? It is up to the children to choose whether to use multimedia tools to make software directly. Then form different study groups on this basis.
In this way, each exhibition hall has become the research object of students, and the children try their best to collect information around their own tasks. For example, they go to the corresponding exhibition hall of the zoo to observe the habits and ecology of animals on the spot, and go to the library and the Internet to inquire about relevant information in order to obtain animal pictures and write instructions. After each group completed the assigned task, Mary organized the whole experimental class to exchange and discuss. This autonomous inquiry learning mode around certain situations not only greatly promotes students' learning consciousness, but also fully embodies students' cognitive subjective role. Moreover, cooperative learning based on this will be an effective way to deepen students' understanding of concepts and help students construct knowledge meaning as long as teachers guide them properly. For example, when demonstrating the animal kangaroo in class communication, Mary asked the class a question: "What is a marsupial? Are there other marsupials besides kangaroos? " Some students cite wombats and kangaroos. So Mary asked the students to discuss the similarities and differences of these three marsupials, so as to exercise and develop the children's ability to distinguish and compare things in the relevant background. This is another example of using multimedia computers and the Internet as cognitive tools to realize a constructivist learning environment, thus effectively helping students to construct the meaning of what they are currently learning and promoting the development of students' cognitive ability.
Second, the development trend of multimedia education applications
Combined with various foreign educational technology magazines (such as ET, ETS, EMI, JRCE, AJDE ...) in recent years, compared with the previous "ED_MEDIA" World Congress (namely "Educational Multimedia and Hypermedia" World Congress for short, which is the largest international conference on multimedia education applications held once a year in the world), we can see that the current multimedia education applications are worth noting as follows.
1. the combination of multimedia technology and network communication technology
At the end of 1995, one of the most striking events in the field of international information was the launch of "WWW browser HotJava" by SUN Company of the United States on the Internet, which was a brand-new dynamic executable browser developed by SUN Company in Java language. Its outstanding feature is its animation function, which can provide users with graphics, images, sounds, animations, cartoons and other media information in hypertext format; And static documents can be turned into dynamic executable codes, which completely changes the situation that Internet browsers can only be used to query and retrieve information on the Internet, and opens up new broad prospects for the educational application of the Internet, because the dynamic executable characteristics of HotJava are tantamount to giving users a remote interactive function. For example, one user can use HotJava to write a Java application to realize a page simulating a chemical reaction, while other 3W users can not only see the simulated page, but also interact with it using HotJava browser (for example, some parameters in the chemical reaction process can be changed to observe different reaction processes and results). Using this dynamic executable feature of HotJava, users can not only see static pages when searching some important documents or teaching materials, but also see the visual demonstration of simulation experiments or algorithm execution process by clicking an icon or hotkey. Obviously, this interactive function is essentially different from the effect that the first generation Internet browsers (such as Mosaic and Netscape) can only view static pages, which is of great significance to educational applications (especially distance education applications). It can be said that the appearance of HotJava is not only a great innovation of Internet browser, but also an ideal combination of multimedia technology and network communication technology. Since then, the application of multimedia education based on the Internet has been developing day by day (in the 12 1 multimedia education application paper exchanged at the ED_MEDIA World Congress held in Boston, USA in June this year, an educational application paper combining multimedia technology with network communication technology was realized by using 3W server and HotJava *. At present, not only the western developed countries are vigorously developing the application of multimedia education based on the Internet, but also Taiwan Province Province, Hong Kong and other regions have invested considerable manpower and material resources in this field (at present, almost all the main players in Taiwan's educational technology field have invested in this research field). This is a new trend worthy of our attention in the application of multimedia education, and it is also the fastest developing trend at present. We must catch up.
2. Combination of multimedia technology and simulation technology.
The combination of multimedia computer and simulation technology can produce a strong illusion, which makes people in it throw themselves into the current virtual reality world and have no doubt about its authenticity. This technology is often called "virtual reality" (VR for short). In other words, virtual reality is an interactive artificial world produced by the combination of multimedia technology and simulation technology, in which an immersive and completely real feeling can be created. When you enter the virtual reality environment, you usually need to wear a special helmet (head_mounted display), which can let you see and feel the whole artificial world generated by computer. In order to interact with the virtual environment, it is also necessary to wear a pair of data gloves-it enables the wearer not only to perceive but also to operate various objects in the virtual world.
Due to the expensive equipment, VR technology is mainly used in a few difficult military and medical simulation trainings and some research departments. However, VR technology has irreplaceable and very encouraging application prospects in the field of education and training, so this development trend should also attract our attention. For example, an "interactive multimedia virtual reality system" developed by Dartmouth Medical College allows medical workers to experience and learn how to deal with various battlefield medical situations. Interns who use the system can feel the dangerous symptoms of various patients caused by computer simulation, and they can choose some operating rules from the system to deal with the current injuries, and they can immediately see the consequences of such treatment. In order to give interns a deeper experience, the system can also simulate various surgical operations, including general surgery to complex human organ replacement. This virtual environment enables medical college students to practice various practical operations repeatedly in the ward without taking any risk of medical accidents, and try to choose different technical treatment schemes to test whether their judgments are correct and train certain skills.
Another example of the application of VR technology in education is the creation of a virtual physics laboratory. According to its own nature, physics has put forward many questions about "What if?", which is best explored by directly observing the effects of physical forces on various objects. Researchers from the University of Houston and the Johnson Space Center of NASA have established a system called "Virtual Physics Laboratory", which can be used to intuitively study physical phenomena such as gravity and inertia. Students who use this system can do various experiments including the law of universal gravitation, and can control and observe various phenomena caused by changing the magnitude and direction of gravity and their effects on acceleration. In this way, students can get first-hand perceptual materials (direct experience), so as to achieve a deeper understanding of physical concepts and laws.
VR technology has also achieved remarkable results in chemistry teaching. Scientists at the University of North Carolina have developed a virtual reality system that allows users to manipulate molecular movements by hand. Users can put on helmets and use data gloves for feedback control, so that molecules can be combined in some way. It is not difficult to see that this VR system is not only of great significance in teaching (for example, the molecular structure of protein can be directly observed), but also of great value in scientific research, because the molecular structure combined in a new way is likely to be a new drug for treating a certain disease or a special material needed in industry.
With the in-depth study of multimedia technology and simulation technology, the theoretical method of realizing "virtual reality" has also developed greatly. Initially, the application of VR can not be separated from expensive special hardware or auxiliary equipment (such as helmets, data gloves, high-resolution graphics workstations, etc.). In recent years, this situation has begun to change. For example, at the ED-MEDIA World Congress held in June this year, a brand-new system named "QTVR" appeared. This system has been applied to the design and planning of learning city, and its excellent cost performance is amazing! QTVR technology is very different from ordinary VR technology in simulation principle: it does not use helmets, data gloves and other hardware to create illusions, but uses high-quality images taken by 360-degree panoramic photography technology to generate realistic virtual scenes. Therefore, with the support of Windows operating system or Macintosh operating system, users can really feel the same virtual scene as in VR technology with mouse and keyboard (without helmet and data gloves) on ordinary microcomputers (without using high-end graphics workstations).
Students studying urban design and planning can use QTVR system to create a realistic virtual city. When students change the view of the city scene (for example, look left or right, look up or down, move the camera closer or farther away from the target, etc.). ), the observed scene can still be maintained correctly, giving people the illusion of real sightseeing around the city. At the same time, various physical entities in the city (such as buildings, roads, bridges, trees, vehicles and terrain, etc. You can use the mouse to pick it up and manipulate it at will (for example, you can rotate it and observe it from different angles, or you can enter various rooms inside the building to watch it).
Even more incredible, due to the advanced image compression algorithm, the storage capacity of 360-degree high-quality panoramic photos used to represent virtual scenes in cities in QTVR system is unexpected.