Research And Implementation Of Structural Body In Programming Question Auto-Scoring System

Automatic grading of programs in programming language examination is a practical application, is also a key technique of on-line examination system. It relates to many aspects of theories and knowledge, so it is a difficult point. There have been many technical problems unresolved as yet.The automatic grading model of programs is based on idea of program semantic equivalence. Its implement process is analyzing the whole source program, transforming program into system dependence graph, and standardizing program of student and template, eliminating diversification of representation forms of equivalent semantic program, computing their semantic similarity, finally grading student programs by some strategies.Existent automatic grading model of programs can not deal with the programs with structural body. In this paper, we study the syntax and concept of structural body based on an existed model, and improve the original model in the following aspects: increasing the middle representation form of structural body in analysis of morphology and syntax and system dependence graph and abstract syntax tree, adding standardization rules, mainly including type definition, nesting structure, initialization, function invocation, renaming and sequence of program sentence, besides standardization rules of bit operation and program with enumeration, enhancing the function of inspecting syntax error and improving matching strategies.The improved model has been integrated into"on-line exam system for C language". It has been proved that the model and method are correct and practicable after applying the exam system.