Experimental Discovery Teaching Mode Characteristics

Guidance - Discovering Teaching Models and Teaching Cases

Chen Yaxian

Teaching model refers to the stable structural form of the process of teaching activities carried out in a certain environment under the guidance of certain educational ideas, teaching theories and learning theories. The abbreviation of the process of teaching activity is usually called "teaching process". As we all know, the traditional teaching process consists of three elements: teachers, students and teaching materials. In modern teaching, a variety of teaching media are usually used, so the element of "media" should also be added. These four elements in the teaching process is not isolated from each other, not related to each other simply combined together, but each other interconnected, interacting with each other to form an organic whole. Since it is an organic whole must have a stable structure, by the teaching process of the four elements of the formation of a stable structure, called "teaching mode".

I. Introduction - the discovery of the teaching model:

1. Background:

At the beginning of the 21st century, a new round of basic education reform in our country to start up. This round of basic education reform is aimed at comprehensively promoting quality education, cultivating students' innovative spirit and practical ability, and laying the foundation for students' comprehensive development and lifelong development. One of the goals of the reform set out in the Outline of Basic Education Curriculum Reform is "to change the current situation of curriculum implementation, which places too much emphasis on receptive learning, rote memorization and mechanical training, and to advocate that students take the initiative to participate in the process, enjoy exploring, and work with their own hands, and to cultivate the ability of students to collect and process information, acquire new knowledge, analyze and solve problems, and communicate and cooperate with each other. " However, for a long period of time from the 1950s to the present, biology classroom teaching in China, like the teaching of other disciplines, has been based on the "teacher-centered" teaching model established by Kerov in the former Soviet Union in the 1930s, i.e., "Organize teaching --Reviewing the old lesson - Teaching the new lesson - Consolidating the new lesson - Arranging homework The "teacher-centered" teaching model is "organize teaching - review old lessons - teach new lessons - consolidate new lessons - assign homework". In this mode of teaching, the teacher is the active educator (knowledge transmitter, inculcator); students are passive recipients of external stimuli, the object of knowledge inculcation. Obviously, this teaching mode can not adapt to the needs of the development of curriculum reform. To overcome the shortcomings of the traditional teaching mode, we must put the focus of reform on the students' "learning", from the "teaching" teaching mode to focus on the "learning" mode of teaching change.

2, the theoretical basis:

① American cognitive psychologist Bruner advocated the discovery method, also known as the exploration method, problem teaching method. It refers to a method in which the teacher guides the students to learn concepts and principles by just giving them some facts (examples) and questions, so that the students can actively think, independently explore, discover and master the corresponding principles and conclusions on their own. It is guided by the idea that the student is the main body, independent realization of the cognitive process.

② Constructivist learning theory: Constructivism is the view that knowledge is not imparted by the teacher, but the learner in a certain context that is the socio-cultural context, with the help of other people (including teachers and learning partners), the use of the necessary learning materials, and through the way of meaning construction and acquisition. Because learning is in a certain context that is the socio-cultural context, with the help of other people, that is, through interpersonal collaborative activities to achieve the process of meaning construction, so the constructivist learning theory that "context", "collaboration", Therefore, constructivist learning theory considers "context", "collaboration", "conversation" and "meaning construction" as the four major elements or four major attributes in the learning environment.

Under the guidance of the above educational ideas, teaching theories and learning theories, and according to the actual situation of the biological sciences based on experiments, in the practice of teaching, the application of the guidance - discovery teaching mode can be adapted to the concept of the new curriculum, pay attention to the process of students' knowledge acquisition, and the formation of a positive and active learning attitude.

The basic procedure of the guided-discovery teaching mode

The basic procedure of the teaching of this mode is: problem - hypothesis - verification --Summarize and improve.

1. Problems

The teacher, on the basis of creating teaching conditions and environment, puts forward the problem and guides the students to think positively.

2. Assumptions

Teachers try to guide the students in the evocative problem situation through analysis, synthesis, comparison, analogy and other methods of assumptions, and reasoning around the assumptions, guiding them to reorganize the existing knowledge of various fragments from different angles, from which they find inevitable links, and gradually form a more correct concept.

3. Verification

The use of other similar examples to test the concepts obtained against the correctness and the degree of correctness, relying on further qualitative analysis to make a clearer judgment.

4. Summarize and improve

Guide students to summarize the nature of understanding and its development process, to find out the regularity of things, in order to find in the later understanding and development of further reference.

Three, the teaching case - transpiration makes a large amount of water loss

This is the human education version of the experimental textbook of compulsory education curriculum standards, "Biology," seventh grade, unit 3, section 3 of the content.

Before class the teacher instructs two students

Prepare the experimental materials: branches with leaves, conical flasks with the right amount of water, transparent plastic bags, and thin thread.

Preparation of the experimental setup: ① leafy branch inserted in a conical flask filled with water

② transparent plastic bag on the branch, and near the mouth of the bottle with a thin line to tie the bag tightly, but not with the mouth of the bottle is also tied.

③ Put the experimental setup in the sunlight for some time.

The class, the teacher first created a scenario, the introduction of the new lesson: we know that the home planted plants and trees, crops should be watered regularly. According to scientists: a plant of corn in the growth of the peak, a day to absorb several kilograms of water, more than a day of drinking water, why do plants need so much water? Please two students on the podium to do a demonstration experiment, first show the experimental setup, introduced before class is how to prepare, so that other students after observing, say the experimental phenomenon (a lot of water droplets on the wall of the plastic bag), and then put forward the problem that must be solved: these droplets come from where?

Step 2: analyze and speculate, make assumptions. To the question posed, the students after thinking, speculate on a variety of answers. For example, there are two possible sources of water droplets: one is from the evaporation of water from the bottle, and the other is from the inside of the plant. Obviously, since the plastic bag was not tied tightly at the mouth of the bottle, the water vapor inside the bottle could not enter the plastic bag, so this hypothesis was rejected, so only the second possibility.

Step 3: Collect information and verify. Teachers can guide students to start from this aspect: if the assumptions just made are valid, I will further ask: the plant body water is through what pathway, in what form is emitted outside the plant body? Guiding students to review related knowledge, such as how root hairs absorb water, the pathway of water transport in the plant body, students through group discussion, review the old knowledge, and finally summarized: water in the soil is absorbed by the root hairs through the root conduit upward transport to the stem, and then transported through the conduit in the stem to the leaf, into the leaf pulp cells. Teachers further proposed: water into the leaf pulp cells, how to dissipate out? Ask the students to observe the structure of the leaf through an experiment. Students conduct group experiments in groups of two at the same table and try to make clinical slices by freehand slicing, put them under the microscope and then observe the permanent slices of the leaf. Through observation, they recognize the structure of the leaf and know that the lower epidermis of the leaf has many stomata. Then the students were guided to associate that the water in the plant body is emitted in the form of gas through these stomata. Then, through reading the textbook related content to understand the stomata opening and closing.

Step 4: Summarize and improve, deepen the transfer. It is pointed out that transpiration is the process by which water is emitted from the body in a gaseous state to the outside of the body. Then further asked: 99% of the water absorbed by the plant is used for transpiration, only 1% is used for photosynthesis and other physiological processes, is this a waste? Guide students to think further about the significance of transpiration. The use of multimedia courseware, show the whole process of water transportation and loss in the plant body, and at the same time with the knowledge learned in elementary school nature class, geography knowledge, through group discussion, summed up the significance of transpiration: ① transpiration can lead to the absorption of water and inorganic salts in the plant body and upward transportation. ②Transpiration can reduce the temperature of the plant body ③Transpiration can increase the humidity of the atmosphere and increase precipitation.

Then, the transfer of knowledge is realized through relevant exercises.

Four, the implementation of guidance - the effect of the discovery of the teaching mode:

1, in this mode of teaching teachers and students in a collaborative relationship, through the students actively explore the research to obtain new knowledge, so that students learn how to learn, how to find out how to present problems and how to carry out the processing of information, how to put forward the hypothesis of how to reason and verify, cultivate the students' scientific investigation and verification, cultivating the ability of students to scientific inquiry.

2, conducive to the cultivation and development of students' logical reasoning ability and scientific rigorous way of thinking, in order to meet the rapid development of science and technology on the teaching of knowledge and mastery of knowledge put forward by the new requirements.

3, conducive to stimulate students' interest in learning, and promote the formation of a variety of outstanding qualities. Teachers in the teaching process, make full use of novelty, doubt, difficulty, contradiction and other factors to cause conflict in the thinking of students, so that they take the initiative to find problems and thinking about the problem, and then actively solve the problem, which can make the students interested in the course of study itself, and enhance the independent discovery and solution of all kinds of practical problems, and in the discovery of knowledge in the process, and gradually formed indomitable strong perseverance and climb the peak of scientific and technological awareness. The process of knowledge discovery, and gradually formed a strong perseverance and the courage to climb the peak of science and technology enterprising consciousness.