Study On Automatic Scoring System Applied To Paperless Test Of C Language

With the progress of the updating of educational thought and science and technology, a large number of maladies of traditional test mode which uses paper and pens as the major tools arise as time passes, especially in the test methods of computer knowledge. Aiming at the current situation, computer paperless tests emerge because of demand. This advanced test mode not only objectively and fairly reflects the true level of the learners, but also save manpower and resources and improve the testing efficiency,C language is a high-level programming language which is widely welcomed because of advantages such as powerful functions, flexible use, efficient object program, good portability and so on. Many computer majors and science majors in all kinds of colleges have already designed this course. However, at present the merit rating of this course still adopts the traditional method, namely, the teacher sets the papers for the examination, and after the examination, the teacher looks over the examination papers one by one , and then records the results. This test mode can only exam the degree of students'grasping theoretical knowledge of C language, but it can't exam their capacity and level of practical application. So it results in the phenomenon that students attach importance to theory but look down on practice. Meanwhile, the traditional manual marking mode has a lot of defects: it wastes lots of manpower and resources; work efficiency is low; subjectivity is strong. Aiming at the problem existing in the test of C language, the writer researches and develops the automatic scoring system applied to paperless test of C language. The purpose is to scientize the test of C language, to decrease the workload of marking the papers, to improve the veracity and impartiality of scoring process. The paper elaborates on the guideline , correlation technique, functional design and realization. The paper carries on the research and design at test question bank, component test paper, examination and automatic scoring, and the emphasis and difficult point lie in scoring design for program questions in the automatic scoring system. The module of component test paper is the module of the test question bank that can randomly elaberate test questions according to the preset parameter and generate test papers through the form of test question banks. The test items include multiple-choice question, fill in the blanks, correct mistakes in the program and programming. The module of topic test can realize the switching of the test interface and programming language environment, therefore complete the test. This module can guide the examinees to take the test by human-computer interaction mode through the screen, and require the examinees to store the answers in the prescribed document in order to be used when somebody grades. The module of automatic scoring is the core of the whole system and the difficult point as well. The author carefully analyzes and researches the above-mentioned four test items and adopts different marking methods to different test items: to multiple-choice questions, use the method of comparing simply; to fill in the blanks, use the method of character string comparing; to correct mistakes in the program, use the method of combining adding signs with character string comparing; to programming, the author has a brave innovation, that is, the scoring process not only adopts the traditional result comparison, but also adopts the method of combining dynamical marking with static marking, namely, when the examinee program has only a few mistakes, we find and correct the mistakes dynamically through lexical analysis and syntax analysis. Thus, we can mark according to the result information and error information; when the examinee program has serious mistakes, we mark statically. The concrete implementation procedure is: the system sets up lots of key statements in the test question bank document about programming questions in advance according to the test questions. When marking, we give a mark by testing the number of key statements in the examinee's program. The scoring method is closer to traditional scoring. The mark getting in this way can reflect the examinees'practical level in programming more accurately. Therefore, we guarantee the fairness and reasonableness of the scoring.The system is realized by using Visual Basic, C language and Fundamentals of Compiling, etc. .The design of all kinds of interfaces and the establishment of various test question bank of test items are finished by Visual Basic. For grading and correcting arithmetic about the programming questions, C language compiling is adopted. Furthermore, the debug and correcting mistakes functions of programming questions are realized by lexical analysis and syntax analysis through fundamentals of compiling. The grading and correcting mechanism adopt obligate mechanism , forward probe mechanism and backtracking mechanism.The system has the following innovations in realizing the function of programming automatic scoring:1. The fault-finding and mistake-correcting handling of the examinee program.2. To translate and edit the examinee program in the program.3. To run the examinee program in the program and avoid system crash.4. To test the logic rationality of the examinee program.The system realizes the test on computer and automatic scoring of C language course and improves the imperfect factors in the traditional testing system to make the test items more plentiful and the results more reasonable. By using this system, we can realize the testing on C language course and the results of scoring can faithfully reflect the practical result of the examinees. It has been preliminarily proved that the system has advantages like beautiful interface, simplified operation, steady operation, high reliability and strong practicability through the using in a small range. The research, expansion and application of Automatic Scoring System Applied to Paperless Test of C Language can promote the reform of examination method, carry out a modernization of investigating the means, can ease the teacher's workload in the meantime, lower handicraft to grade examination papers decrease the influence of the subjective factor of the people who are in charge of the papers sooner and soon, more objective, organize examination work more safely, with realization examination automating of process with scientific, carry out the modernization of teaching management.