Design And Implementation Of The C Program Online-test System Based On Campus Network

Wih the rapid development of computer network technology and the popularity ofCampus Network, the computer online-test system has been accepted by more and moreschools."C programe"is a main subject for science and engineering students in marycolleges, Every year the school need to expend a large amount of manpower and materialresources to arrange the final exam. On the base of analyzing the present situation of thecomputerized test system, and using mature technology, such as ASP, JavaScript, SQLServer and Stored Procedure, this paper designed and realized a"C program online-testsystem based on campus network". The system is based on B/S model, it can implement aseries of functions relating to examination, such as users management, test questionsmanagement, question extraction, paper forming, on-line test, paper marking, score andpaper query. The system can reduce the teachers'work intensity greatly, improve theefficiency, while avoiding the problem of inconsistent grade and score calculation error byteachers, to ensure the fairness of the examination, and the system can also be effective inassessing students'actual programming and debugging level, that will encourage students tofocus on hands-on training and improve their practical abilities.The system divided users into three types of permissions: student, common teacher andadministrator. student can take part in formal examination and mock examination. commonteacher in charge of their own students information management, can also view and save testscores and marked papers. administrator has the highest privilege in the system, in additionto common teacher's Permissions, but also for other important work , including: teachersinformation management, test question maintenance, setting test information, extractingquestions to form paper and marking exam papers.The main features of this system are as follows:Using"Iframe"as a "hidden intermediary" in the data transmission process when thedata submited on the web page. Iframe is a form of framework , it can be embedded in anypart of the web page, by use of iframe we can embed one web page into another webpage. We use iframe for this feature, the current page embedded another page forsubmission which has a form in it. When we click the "submit" button to submit the formwhich we filled out in the current page , the page is not sent the form data directly to the destination page (such as the checking page), Instead, the data assigned to the form elementswhich in the embedded page.Then the embedded page will send the form data to destinationthrough the submission operation. During the data transfer process, the current page just dosome assignment, so there will not appear page jump phenomenon .We set iframe's heightand width zero, and define the type attribute of form elements in embedded page as hidden,then the web page which embedded by iframe completely disappears, it is " hidden ". So theuser operation experience is: When he submit a form on a web page , The current page cankeep still while data transmitting, and a message box will Pop-up to Show whether datatransmission successfully or not .The method of using iframe as a "hidden intermediary" to submit data is popular usedin this system, such as user login, submit answers in paper, test question management.Avoiding the common phenomenon of web page jump back and forth in the traditionalsubmission page.So the interface will become very comfortable for users.A very convenient way to switch between online-exam papers page and VC which Cprograms can be debugged and executed. Inspired by the C-Level computer test systeminterface, this system used"JavaScript ActiveXObject""to achieve such an effect as follows.When student do program correction question, program filling question and programming,just click " Enter VC for beginning " button, he can go directly to VC environment, and thesystem can open the source code automatically for the title, student can edit ,debug andexecute program in VC, then click"submit" button on the test system to submitanswers. This measure made the use of the test system is very simple and convenient.According to the different needs of the actual situation, this paper realized three strategyof exam question extraction. When the question bank is large enough, you can use thecommon random strategy for extracting questions to ensure that each student's paper on thesame amount, the same level of difficulty, but the specific subject is not the same. If thecurrent test bank relative to the number of students is not big enough ,to avoid leaking examquestions, you can choose group extraction strategy. The system realized two type of groupsextraction strategies: grouping and extracting according random, grouping and extractingaccording student ID. The former applies to the casual arrangement of examination room;the latter applies to the examination room arrangement ordered by student ID, ensure that theadjacent position papers certainly not same.The system realized the function of marking exam paper automatically by computer,especially for programming can also give a reasonable score. In the system, computer canscore every question on the test paper, including: choice, fill-in-the-blank, program correction, program filling and programming. Among them, the problem of automaticmarking programming question is a difficulty in test system. To judge a program right orwrong, based on its operating result. If the result is right, then get all score, else should givescore according submitted code. The system uses the input file test program's run results,with the grading standard support, better soluted the program automatic correcting.This system not only allows teachers to query and save test scores, but also permitteacher to view and save the marked paper which contains the student's answers, thestandard answers, and marking comments.The system made full use of the SQL Server stored procedure technology, not onlyimproves the system efficiency, reduces network congestion, and also contributes to thedatabase table structure protection.In summary, this paper designed and implemented a C online-test system, introducedthe main functions and the key technology. Its main characteristics are extracting questionsby group strategy, paper automatic marking, and embedded web page with iframe for datatransfer.