Case study of scientific inquiry experiment and experiment report

Case study of scientific inquiry experiment and experiment report

Chen Yu, Cao County Second Middle School, Heze, Shandong


Abstract: Scientific inquiry experiment is the key point of the new curriculum, and it is also the hot spot, highlight and difficulty of the current basic education curriculum reform. This article explains the six elements of scientific inquiry one by one, and shows examples of how to do scientific research experiments and how to do experimental reports.
Keywords: scientific inquiry, scientific inquiry, experimental experiment report, problem diagnosis, hypothesis, experimental data processing

As the hotspots, highlights and difficulties of the current basic education curriculum reform, the "Ordinary High School Physics Curriculum Standards" puts forward clear requirements for scientific inquiry, and points out: "The high school physics curriculum should promote students' independent learning, let students actively participate, be willing to explore, and be brave. Experiment, diligent thinking. Through a variety of teaching methods, help students learn physics knowledge and skills, cultivate their scientific inquiry ability, and gradually form a scientific attitude and scientific spirit." Generally speaking, we must follow the following scientific inquiry Step or process:


First, ask questions

“The father of modern science,” Einstein once pointed out: “It is often more important to ask a question than to solve a problem, because solving a problem may be just a mathematical or experimental skill, but a new question, a new one. Possibilities, looking at old problems from a new perspective, requires creative imagination and marks the advancement of science."

The problem is the pioneer of creation, the starting point of thinking. The problem consciousness is the premise and foundation of one's innovation. Whether it has the problem consciousness and whether it can raise valuable questions is the watershed of the old-fashioned people and the pioneering and innovative people.

The questions we ask should first be scientific, not anti-science or pseudo-science, but must also be valuable, meaningful, instructive, and worth exploring. According to the students' existing knowledge, the problems we can raise should be rooted in life, but higher than life, but not from life and practical experience. The questions raised should be within the limits of their ability, that is, the ability to apply existing physics. Knowledge, coupled with some unknown physical knowledge, is solved using scientific methods and ideas, either independently or in collaboration.

After asking a question, we must also clarify the problem. The problem is to lay the foundation for making a hypothesis or a bold guess. This problem is more clearly explained from the perspective of physics.

Second, conjectures and assumptions

Let students make assumptions and conjectures, based on existing physics knowledge and experimental experience, make guesses and assumptions about the way to solve problems and the answers to questions, and predict the experimental results.

Einstein said: "Imagination is more important than knowledge, because knowledge is limited, but imagination sums up everything in the world, promotes the advancement of science and technology, and is the source of knowledge evolution. Strictly speaking, imagination is in scientific research. Real factors.” Mr. Qi Tingjun believes that high school students have the ability to abstract logical thinking based on theory, which is embodied in: 1 students can think through hypothesis. According to the way of asking questions, clarifying problems, proposing hypotheses, and verifying hypotheses, through a series of abstract logic processes, the goal is achieved. 2 Student thinking has been presupposed, and students have taken certain methods and means before solving problems. 3 Student thinking has gradually evolved. Middle school students gradually develop from the dominant position of specific computing thinking to the dominant form of formal thinking. They can not only carry out the induction from special to general, but also perform the deduction from general to special. In their practice and study, high school students have been able to complete the complete process from concrete rise to theory and then theoretical guidance to obtain specific knowledge. 4 The awareness of self-awareness or monitoring ability in high school students' thinking activities. 5 Students' thinking can jump out of the old frame, creative thinking has been rapidly developed, and began to pursue new and unique things, forming their own unique views on things. To this end, teachers should encourage students to boldly guess, only imagine, can break through the old knowledge as much as possible, break the limitations of time and space, and think about the problems raised by themselves as much as possible. Reasonable or bold conjectures often sparkle with wisdom. Unintentional intuition can often open the door to solving problems, stimulate creative inspiration, and exert their imagination. A bold and well-founded judgment can often break through layers. The layer of the group to achieve the purpose of inquiry.

Third, develop an experimental plan

The plan is a kind of idea, it is a presupposition, and it can only be perfected after many attempts; the plan is a street lamp, which is a lighthouse, guiding us to complete the experiment or the set goal in a step-by-step manner. The quality of the scheme design is directly related to whether the experimental steps are orderly, whether the experimental data is true and reliable, whether it is reliable or not, and whether the experimental conclusions are representative and universal. Galileo's ideal bevel experiment is just as good as the experimental design, the design is reasonable, and the design is natural. To this end: the equipment in the 1 program should be selected reasonably, easy to prepare, and cannot be too high. Before you determine the experimental plan, you should first learn the correct operation and skilled operation, paying particular attention to the matters that should be noted. 2 The inquiry process should be as clear as possible, the connection between the steps should be smooth, and the form design should be reasonable. The experimental plan should be determined as much as possible, and the experiment should be carried out as much as possible, and the advantages and disadvantages of each plan should be compared to determine the best solution. If one of the experiments is confirmed to be unsuccessful, other experimental protocols can be selected as soon as possible.

Fourth, conduct experiments

According to the experimental scheme, follow the instructions in the manual operation, pay attention to safety during operation, record the data and experimental phenomena in the experiment, use observation, experiment or other methods to collect experimental data and information in multiple channels and forms.

Collect experimental data and information as much as possible in order to minimize the interference of accidental errors. The more information we collect, the better it is for us to do qualitative analysis; the more data, the better it is for us to do quantitative calculations. Of course, in order to better approximate the experimental conclusions, in addition to experimental means, we can also collect and obtain information from a variety of information sources to make up for the lack of experimental means.

V. Data processing

After sorting out the collected information and information, it is necessary to analyze and process the data. “Apply scientific thinking methods, analyze and summarize, find out the law, try to draw conclusions based on experimental phenomena and data processing, and experiment with The results are explained and described. What feedback can be obtained through the processing of experimental data?

When summing up the experimental conclusions in your own language, it should be noted that the experimental conclusions should generally have the following characteristics: 1 The conditions are quite strict and cannot be expanded or reduced arbitrarily; 2 The experimental methods are quite perfect, and of course there are places that need further improvement; Strict, should be described in rigorous and accurate scientific terms, and have quite rigorous logic.

Sixth, experience and experience

Through experiments, learn the lessons of failure and accumulate successful experiences. After the experiment, an experimental report should be submitted, in which the research ideas, processes, methods and conclusions should be scientifically expressed. Most of the players who have played football games know that "we must pay attention to their own positive breakthroughs in the competition, but also pay attention to the unity and cooperation of the team." In the scientific inquiry experiment, self-independent inquiry and communication are also just as important. In cooperation, we must adhere to our own principles, have our own thoughts, have our own opinions, have our own experimental programs, and be able to actively listen to the suggestions of others and respect the opinions and achievements of others. Only when we personally experience scientific inquiry can we gain a habit, develop a consciousness, and foster a kind of ability, which is extremely important for us to learn in our future.

The following is an example of the experiment of "exploring the relationship between acceleration and mass and force", and briefly discusses how to conduct scientific inquiry and write experimental reports.

Experimental principle and experimental scheme: Newton's first law tells us that force is not the reason for maintaining the motion state of an object, but the reason for changing the motion state of an object. In short, the change of the motion state of the object is reflected in the change of the speed, and the change of the speed indicates that the object has acceleration, so it can be said that the force is the cause of the acceleration of the object. The same as a stationary car, the greater the traction applied, the shorter the time required to reach a certain speed. From this we can assume that the acceleration and force become a linear function a = kf + b, while assuming b = 0. If the assumption is true or not, it needs to be explored and verified experimentally. At the same time, the greater the mass of the object, ie the greater the inertia, the harder it is to change the motion state of the object, ie the smaller the acceleration, so we can assume a=b+1/km and assume b=0. Therefore, the acceleration we are going to explore now is related to force and quality at the same time, so what is the relationship? According to the philosophical point of view, the change of the state of motion of the object is determined by the combination of external force and mass. The two factors of external force and mass are unified in the process of changing the motion state of the object, and at the same time contradictory. The external force promotes the generation of acceleration, and the quality remains unchanged, which hinders the generation of acceleration. In physics, the basic method of studying a multivariate problem of physical quantity and two or more physical quantities at the same time is to control the variable method, that is, to keep the other physical quantities unchanged, and gradually analyze the relationship between the physical quantity and one of the physical quantities, and then Summarize the relationship between these several quantities. Therefore, we can first fix the mass and explore the relationship between acceleration and force; then fix the external force and explore the relationship between acceleration and mass; finally, summarize the relationship between acceleration and external force and quality.

If a=k1f is established, it should be a straight line that is over the origin of the af plot. If a=k2m is true, it should be a hyperbola on the line of the am, but it is true whether the line is true. The hyperbola is more complicated, but we can change the angle and convert a to m in inverse proportion to a proportional to 1/m, that is, the a-1/m line is a straight line passing through the origin. However, the acceleration is not easy to measure, so we need to convert it into displacement, and what we are looking for is mainly the relationship between a and f and m. From another angle, it also shows that the actual value of a is not needed. During the design experiment, the car will make a uniform linear motion with an initial velocity of 0. At the same time, the car will be placed in the same position, and the folder will be opened and closed at the same time to make the movement of the two cars equal, from s=at2/2. It can be found that a1/a2=s1/s2. This converts the acceleration into a displacement, which is much better in the future.

The textbook gives the experimental setup, but it is not very good. On the one hand, there are no strict smooth horizontal boards. The boards in ordinary laboratories are mostly rough and do not meet the experimental requirements. On the other hand, if you put the weights in the small dish, many students are not evenly placed. It is easy to bring considerable errors. The improved experimental setup is shown below:

Experimental equipment: two small carts with grooves on the top, two long straight planks with fixed pulleys at one end, one large data clip, a number of weights, a number of hook codes, a number of thin lines, and a scale.

In order to record the acceleration of the car, we can use the paper tape, and in order to avoid the collision between the car and the fixed pulley, we can lick two long thin wires behind the car and fix the other end of the thin wire. The experimental scheme discards the weight plate, and the use of the bar code can ensure that the pulling force is in a straight line, and the increase or decrease of the bar code changes the pulling force of the car. The quality of the weight is increased or decreased on the trolley, which changes the quality of the trolley.

In order to obtain a nearly smooth long straight board, we usually use the method of balancing friction: no weight, no thin line, try to move the skid, so that the car placed on the slope is similar to a uniform linear motion, at this time the object It is balanced by the three forces of g, n and f. The resultant force is 0, and gx=f. The effect of the two forces cancels each other, which means that f does not exist. When the trolley is pulled by the thin wire, it is equivalent to only