The Automatic Marking Method Of Script

The database technology is one of the core of computer science courses, and the basis course for other various professional courses. So far the test and correcting homework of this course is limited to manual scoring. With this approach, it takes heavy workload and it is low efficiency, and the objectivity is limited by the experience of the reviewers. It can not meet the development needs of computer education. Paperless examination becomes the trend of development, and the automatic marking can freed from the heavy work and improves the work efficiency greatly.For SQL scripts of database tests, this paper put forward an automatic marking algorithm based on parsing and string edit distance. Firstly, through the lexical analysis and syntax analysis for the student answers, the syntax analysis tree is obtained and save it as XML files. Secondly, the most matched standard answer is chosen from the standard answer sets by comparing the string edit distance between the student answer and the standard answers. Thirdly, by comparing the similarity of all the corresponding nodes of the two syntax analysis tree, the mark is achieved based on the score value of the standard answer. The marking system is implemented using open source parser-ANTLR3.4and VS2010, which can not only gives reference score, but also points out the error position. Furthermore, it supports efficient and accurate marking for multi-answers answers with fault tolerance.Experimental results show that the automatic marking method proposed in this topic is some executable and valid, but there are some issues affect the scoring accuracy. Finally this paper put forward the solution t for this problem.