The content of primary school science curriculum includes three areas: life world, material world and earth and universe. Among these three fields, some contents of "Earth and Universe" are relatively difficult to teach, especially the universe unit in the sixth book of science, which is the content of primary school students' first contact with celestial stars. Because the celestial bodies are far away from pupils' lives, and pupils' abstract thinking and spatial imagination are limited, it is often difficult to learn and understand, so the teaching of this unit is difficult and the learning effect is poor. For teachers, due to the lack of professional knowledge reserves and support for the teaching of cosmic celestial bodies, teachers are also facing great challenges to the teaching content of this unit. However, influenced by the current teaching evaluation, students need to master more knowledge points in this unit. Therefore, there is a common phenomenon in teaching that teachers indoctrinate students instead of exploring independently, and "teach" for "examination" and "learn" for "examination". This will not only make students unable to fully understand and master the knowledge of the universe and celestial bodies, but also make them feel tired and afraid of learning, thus affecting their interest in exploring the universe and the basis of science teaching. How to change this "double fear" dilemma that teachers are afraid of teaching and students are afraid of learning is a realistic topic in front of our front-line teachers.
Cause analysis of this problem.
Analysis of this "double fear" situation mainly has the following reasons:
From the teaching content: although we live in the universe, there is a big gap between it and our time and space (relatively speaking, the time and space in the universe is macroscopic and abstract, while the time and space we live in is microscopic and concrete), and we lack concrete life experience and feelings about phenomena, thus affecting our understanding and mastery of knowledge. Although this unit teaching is only the initial content of cosmic knowledge, there is still a lot of knowledge to be mastered, such as the change of moon phase, the formation of solar eclipse, the composition of solar system, constellations and so on. This knowledge is far from students' life and experience, so the understanding of knowledge is "embedded", rather than a deduction, induction and promotion based on the original knowledge and life experience. It is difficult for students to know why and why in teaching.
Judging from students' thinking ability, primary school students' abstract thinking and spatial imagination are poor, and they are easy to accept things with intuitive images. Abstract things are often helpless, and it is quite difficult to understand the nature and laws of things. Therefore, it is difficult for students to imagine the phenomena of moon phase, solar eclipse and lunar eclipse caused by the relative motion between celestial bodies in the vast universe, which is difficult to understand. Many students can only learn by rote.
From the teachers' own point of view, primary school science is a comprehensive and professional subject, and most primary school science teachers aim at cultivating "generalists" who are qualified for teaching all subjects in primary schools. Teachers themselves lack the support of professional knowledge, and it is difficult for teachers to control the classroom in the face of cosmic celestial knowledge.
Measures and actions taken
Based on the research and analysis of the above problems, combined with our own teaching practice and students' cognitive rules and thinking characteristics, we put forward the "modeling teaching method" to help students understand and master knowledge.
Modeling is simply "modeling". This theory is widely used in the field of mathematics, which refers to a powerful mathematical means to approximate and "solve" practical problems through abstraction and simplification by using mathematical languages and methods. Modeling in this topic only refers to the use of various means and channels to help students build a model of the universe, so as to understand the laws of the operation and change of the universe. The so-called model is a description of the essential attributes of the system in some form to reveal the function, behavior and changing law of the system. Of course, the model is not just an entity that shrinks or enlarges the actual object. The model of science class can be a device, a plan, a sketch or even an imagination. The cosmic space model referred to in this topic not only refers to the miniaturization model of cosmic space, but also helps students to establish a reasonable imagination, so that various celestial bodies in the universe can be displayed and combined in their minds, and a cosmic space model can be formed in their brains. This topic tries to help students build a model of the universe through materials, images, experiments, graphics and activities, so that students can learn to use the model to understand, master and apply knowledge. The specific method is as follows:
First, data modeling.
A good education is based on students' existing cognitive level. Classroom learning is an integral part of students' understanding of the universe, not all that students know and learn. In teaching, we can make use of books, movies, internet and other information resources, so that students can constantly improve and enrich their existing knowledge in the process of collecting and accumulating information. There is no doubt that students usually learn some knowledge about the universe through many channels, but this knowledge is sporadic, independent, incomplete and some even wrong. At this time, the universe in students' minds is hazy and fuzzy. Search materials can be arranged before class to help students replace those incomplete and wrong knowledge in time, so that students can initially form a model of the universe in their brains and prepare for subsequent modeling. The collection of materials in this unit runs through the whole learning process of students. Before class, students are provided with relevant bibliographies, such as 100,000 Why's, Popular Science World for Teenagers, Nature Encyclopedia for Pupils, Astronomy of Science Explorer Series, Space Neighbors of China Youth Popular Science Series (6-9 years old), etc. And encourage students to browse the China Moon Science Network. Ask the students to classify the first-hand written materials according to the content of the textbook. Through sorting and analysis, students initially understand most of the contents of the universe unit and form a preliminary model of the universe space.
Second, image building.
Primary school students' thinking is dominated by images, but their abstract thinking and spatial imagination are relatively poor. The content of unit learning in the universe is close to and far from students. "Near" is because we live on the celestial body of the universe-the earth, and we can see the day and night changes of the sun, moon and stars at any time and feel the changes of the four seasons. "Far" is because the universe is vast, and the range visible to the naked eye is so narrow, and there are still many strange fields that we need to explore in the distant space. Many people are also fascinated by the known universe. In the process of teaching, if teachers only dictate according to textbooks and describe and introduce celestial bodies with concrete and huge data, students will often be amazed and only know how big they are, but they still have a little knowledge of how big they are and the relationship between celestial bodies. Practice shows that although we can remember relevant knowledge by strengthening memory, the knowledge in students' minds is often "fragmented" and cannot form a complete image in their minds, so they cannot understand the vastness of the universe and arouse students' interest in learning astronomy. In teaching, we use metaphor to connect the things and phenomena that students can actually observe with those in distant space, so that they can communicate with each other, thus turning abstraction into concrete, helping students to form a model of space and truly appreciate the vastness of the universe. For example, if the universe is compared to a sea in the Wang Yang, then the part of time and space that we humans know, the total galaxy, is an island in the sea. The Milky Way is just a small stone on the island, and the solar system is a grain of sand attached to this small stone, making the earth smaller. Compare the star to a powerful searchlight, then the planet is just a small firefly standing on the edge of the searchlight; If you stand in the distant space and look at the Milky Way, it looks like a discus thrown in motion from the side, and looks like a big vortex in a torrent from the top. Pictures and videos are also used to show students pictures of celestial body size contrast and videos of celestial body movement. For example, in the lesson of "Solar System", students can be shown a real contrast map of the size of celestial bodies in the solar system, so that they can intuitively perceive it, thus establishing a model of the solar system in their minds.
Third, experimental modeling.
Experiments play an important role in science teaching. The model can also be established through simulation experiments. The simulation experiment can directly reproduce the movement changes of celestial bodies in the universe and help students form a relatively complete model of celestial bodies in their brains. In this unit teaching, the moon phase change caused by the "three-ball" operation of the sun-earth-moon is a major focus of this unit teaching, a difficult point for students to understand and a key point for knowledge examination. In teaching, if only through general explanations and demonstrations, students' understanding generally stays at the level of "rote memorization", and it is easy to forget relevant knowledge, which is manifested in exams, and the error rate is often high. Although our teaching is not only for exams, this phenomenon of losing points is caused by students' ignorance of knowledge. In teaching, we help students build models through simulation experiments: basketball represents the moon (half is drawn with white powder to represent the sun), the blackboard represents the sun, and students sit in the middle to represent observers on the earth. The moon rotates counterclockwise around the earth. Ask the students to record the shape of the moon phase. This simulation experiment breaks the boundary between time and space, and shows the complete phenomenon that takes place in distant space and needs continuous observation for one month or even several months, so that students can form a complete spatial model of the moon's operation in their brains, so that they can understand the law of the moon phase change.
Fourth, plane modeling.
Teaching schematic diagram is a common method to turn abstraction into image, which is generally accepted by teachers because of its obvious characteristics of simplicity, convenience and flexibility. Sketching is also a good way to help students build a model of the universe. For example, in the simulation experiment of solar eclipse and lunar eclipse, asking students to show the positions of the sun, the earth and the moon with schematic diagrams (see the figure below) can not only help students to do the simulation experiment well, but also help them to establish the model of the moon phase transition and the causes of solar eclipse and lunar eclipse in their minds. In the lesson of "Solar System", on the basis of students' exchange of information about the eight planets in the solar system, draw a schematic diagram of the arrangement order of the eight planets to help students initially establish a model of the solar system, and then let students draw a model of the solar system according to the data table provided in the book, so that students can find that the sizes of the eight planets and their distances from the sun are very different in the process of drawing, so that students can really establish a model of the solar system in their minds and lay a foundation for future study.
Verb (abbreviation of verb) activity modeling
The activity teaching mode has the characteristics of openness and interest, which accords with the characteristics of primary school students' strong thirst for knowledge, good participation and good imagination. It is an important form of primary school teaching. The universe is boundless and mysterious, and it is not enough for students to truly understand the universe. After class, we let students experience interesting and valuable practical activities again and again to help them form a model of the universe structure with certain explanatory power. The typical practical activities of this unit include making moon cards, observing the moon phase during the day, making models of the solar system and the Big Dipper, and observing constellations. For example, making monthly cards, after class, let students make monthly cards in the form of computer slides, word documents or words, and exhibit excellent works. The children are very enthusiastic and have finished it seriously. In fact, the production process is also the process of their modeling.
affect
Through several rounds of classroom teaching practice and research, especially through holding tabloid exhibitions and displaying cosmic images, students' understanding of this unit knowledge has been obviously strengthened. Students' interest in learning knowledge about the universe has been generally improved, and their ability to analyze and solve space problems has also been enhanced. Some classes also set off a craze to explore the mysteries of the universe, spontaneously organized a space exploration team, and used the night or weekend to observe the moon phase and starry sky in the countryside, and the observation report formed participated in the appraisal activities and competitions in international year of astronomy.
Through research, teachers' teaching level and research ability have been improved. Mainly reflected in: teachers read and consult a large number of relevant materials and accumulate rich educational information; Teachers improve teaching efficiency through classroom practice; Teachers have learned the method of project research, and achieved some results, such as: summarizing and writing "Helping students to build models in various ways-some suggestions in the process of unit teaching" won the first prize in the evaluation of scientific teaching papers in the district and the second prize in the city, and two papers were published in provincial journals.
Reflection and follow-up research
In the process of practice and exploration, we also found some problems worthy of attention and deep thought:
1, the research work lacks continuity. The teaching content of the "Universe" unit is only a short month, which means that the specific implementation of the subject is only one month. In the process of implementation, many new problems are too late to be solved, and new ideas can only be perfected in the next round of teaching.
2. The popularity of research results is not wide. Because this study pays great attention to the practicality and pertinence of the topic, and the topic is very single, only the sixth-grade teachers (actually only 1) participate in the study, and the teachers' participation and benefits are not wide, so it is difficult to popularize the application of the results.
3. Observation (observation) lacks overall consideration and arrangement. Observation is still an effective method of modeling and an important method of exploring science. Because the teaching time is relatively concentrated, it is often influenced by weather and other factors in the observation of celestial stars, so it is difficult to achieve the observation (observation) goal.
Therefore, in the next research, on the one hand, more teachers should be involved to enhance the sustainability of the research and the application of the research results; On the other hand, students' observation should be considered as a whole, especially in the nodes suitable for students to observe (observe) the astrological celestial landscape, and news should be released in time to guide or organize students' observation, so as to improve students' interest in cosmic celestial bodies and integrate abstract knowledge into their usual observation.