Analysis of Student Learning Ability in Science Teaching Based on Mid Semester Examination

This Research tried to make description about student ability in science concept that had been being touch by the teacher based on mid semester examination. The population of research is the 8th grade of students taken place at Public School in Padang academic year 2016/2017. Then the sample is 3 (three) Sekolah Menengah Pertama (SMP) with 2 (two) categories are: average and the better category. The result of these studies is the ability of the student in science only in average 60% below to the criteria mastery level for student Kota Padang. Based on analysis of the result, some misconception occurred in 4 (four) concepts of Physic and 2 (two) concepts of Biology. This result have to be followed by the other research that which can provide a how to overcome the problem of learning science among


Introduction
Learning should be described in terms of its content A highly significant aspect of learning is the variation in what is learned, i.e., the diversity of ways in which the same phenomenon, concept or principle is apprehended by different students [1]. Learning outcomes assessment should be undertaken by an educator, not ony for the sole purpose of assigning grades in student report cards, but also can be used for the purpose of mapping the ability of learners in learning a subject. Some.cores epistemic practice. of science and accordingly claim that the goal of science education must be not only mastery of scientific concepts but also learning how to engage inscientific discourse [2]. Analysis of examination results as an important activity that can be done if educators expect a lot of information that can be collected such as the state of student learning outcomes. Science learning outcomes assessment related closely to students ability understanding the concept in science. Concept in science is some situation like events, fenomenon and other that representing by object and its symbol. The symbol of concept may has adifferent form by one country to another. Concepts are things, events, situations or traits that have characteristics that are represented in each culture by an object or symbol [3].
One's understanding of the concept of science can differ from one to another, which is called conception. Conception which is not in accordance with the conception of scientists is called misconception [4]. Some studies about student's misconception have been done. Misconception can be identified using a diagnostic test at the beginning or upon completion of specified science topic [5]. A persistent misconception in biology has been found to have multiple underlying causes which are exploited in a powerful multiple-choice test item [6]. Therefore, the purposes of this study know difficult concepts by students based on the difficulty index, knowing the pattern of student answers to the questions given, and knowing the misconceptions by the students based on answers to questions. Students' ability to learn science will be reflected by their ability to answer questions in the exam. If a student fails to answer a question, they are experiencing misconceptions in the science lesson. In this research, the formative assessment investigated is the result of midterm semester which is conducted simultaneously by Education Office of Padang City (Dinas Pendidikan Kota Padang).

Experimental Method
Thee type of this research is a descriptive or expose facto study that gives a descriptive ilumminative of the phenomenon being investigated. This research tries to describe the situation based on past data like the midterm exam. The population of this study is the students of 8 th grade Junior High School The first step is analysis of difficulty index. The analysis of the difficulty index and distinguishing problem tends to lead to the analysis of items. Therefore, in accordance with the purpose of this study, the analysis is done only the analysis of the difficulty index to see the problems that students are difficult, and the questions according to students easy. A difficult question will relate to the mastery of students on concepts related to science subjects. Problem-level analysis of difficulty will determine very difficult questions; quite difficult (moderate); and the questions are too easy. Thorndike and Hagen provide the limits of very difficult-and-very easy questions are as follows if the difficulty index (P) less than 30%, so it is a very difficult problem, if the difficulty index (P) from 30% to 70% so it is a more difficult problem, and if the difficulty Index (P) more than 71 % so it is very easy problem.
Then, the distribution of student answers is analyzed to see the tendency of misconceptions experienced by students on certain concepts. From the distribution of answers can be proven like what the mindset of students in understanding the science concepts their studied. This analysis is more directed to physics concepts than biological concepts. After that, the analysis of each question related to the misconception that occurs when the student answers the question. The analysis is done qualitatively and presented clearly.

Data Description
The number of samples of this study is shown in table 1.  Table 1 show the number of related samples in this study were 761 students from 3 (three) Public School (SMP) in 2 (two) categories are: average category and the better category. One of school taken place in the center of Town and 2 others faraway from it. The average of learning ability of student is shown at table 2. Table 2   The question is why the value of report cards is still high? The answer is that the value of the report card is not only the value of the semester exam course (cognitive) but has been combined with daily test scores, performance exams and attitude aspect values to the science. Based on the results of problem difficulty level analysis, obtained 6 (six) problems that are very difficult, 18 promlems are more difficult; and 16 problems are very easy such table 3.   Table 3 illustrates 6 very difficult questions, 18 difficult question and 16 very easy question. Problem Number 09 with difficulty (P) = 9%. It is about understanding the weight and understanding of the masses. Students are given a matter of weight differences with the masses. The related concepts are gravity, vector quantity; scalar quantity; units of mass and unit of weight. From this problem it can be concluded that students have not mastered the concept: mass; weight; material; vector; scalar; and units. It is therefore recommended that teachers should have to pay attention to these concepts and explain them to students.
The problem number 16 with difficulty (P) = 14%. It is about the kinetic energy of moving objects. Given two objects A with mass 5kg and object B with mass 6kg. The object is being described with a speed of A = 1 m / s and B = 2m / s. Asked the kinetic energy comparison A and B. 86% amount of students answered incorrectly to this question. They did not understand the comparison of quadratic equations. The related concept is the definition of kinetic energy, kinetic energy formulation, comparing kinetic energy of A and kinetic energy of B.
The problem number 32 with difficulty index (P) = 14% th question about some concept of Biology. There are osteon bones; Cartilage; Prone to hyaline; And prone to fibrous. Eighty percent of students are unable to answer the characteristics of bone with respect to the ratio of the lime Eighty percents of students were not able to sum up vectors in a triangular way. Therefore in the future, teachers should be concerned that for this simple concept, students cannot do it. The problem 20 difficulty Index (P) = 25%. This problem is due to the effort made by a force on a flat plane like the figure 2. Seventy five percents of students fail to find solutions to this problem because they do not care about the unit, and do not change units to uniform units.

Misconception Analysis
Student have many problem about sum vectors as a triangle methode. Many students answered A, to the key point about C. This proves that students are still misconceptionon about vector quantities, and how vector summing is. Because vector has a mount and direction, so the sum of two vector have to follow some special way. Some of physics quantities have two quantities there are scalar quantitity and vector quantitiy. Physics concept such as velocity, acceleration, force, momentum, have two scalar dan vector quantities. Vector analysis can help student to discribe the diagram according to some fenomena was given. Some vector marked by an arrow, so teacher have to explain that the arrow pointed the direction as the direction of vector [8].
Student also have some problem when they answer the question about comparison the kinetic energy of two object that have different velocity. Also discussion about the law of conservation of energy (energy conservation), it appears that students have misconceptions about the law of conservation of energy, so sstudents are still have misconceptions about the concept of kinetic energy. They know that kinetic energy is energy related to motion, but forget the mathematical operations. Especially the mode of quadratic operation and the comparison of two prices in the quadratic ratio. Kinetic energy have a direct relation to the Work (W) which have a scalar quantity only.so they did not have a direction (vector quantity). Because of this two concept are the scalar, its more simple to solve the problem about this concept according to teacher. But in reality its not simple by the student. This study also found some other misconception that happen to the student. When the researcher asked the student: " If two or more cars start at the same time in the same point. How about its velocity? Almost all of student answer the velocity of these cars are same. It also when the researcher ask the student. When two car in the same direction, and one car in one time in posision side by side by the other car. How about their velicity at that time? Almost all of student answer, their velocity at that time in same. That found gave a warning to us; as a teacher; let star lesson from the praconseption of the student, in order to over come this misconception. State that "the coactivation of the misconception at the same time as the correct conception should support recognition of a discrepancy between the accurate input sentence and the entire misconception network. Detecting conflict may prompt a revision or replacement process that could weaken the representation of incorrect conceptions in memory. Encountering an elaboration or explanation about the correct concept could also help to increase the coherence and stability of the representation of the accurate concept in memory [9].

Conclusion
Based on analysis of the results, student had some problem in learning science it's proven by the student learning ability. They learning ability only below to the minimum passing level KKM. Some misconception that happened to the student never thought by teacher before. Teacher had surprised to relized that the student had misconception on a very simple concept according to the teacher. The Minimum passing level (KKM) 80 for science need to be reviewed, considering that it is difficult for the students to achieve. Student should not be manipulated, so that they dont care about the lesson. They believe that they can get the good mark although the did not pass the examination in the passing level. Its is several effort can be planed improving student competence by teachers, principals, supervisors or the other educational practitioners. Start with good intentions, work systematically base on the programme for the adventage of young generation.