Abstract
Technological improvements enhanced our education experience and involved new terms like distance-learning. Todays education systems are need to be supported by new architectures managing course, instructor, student, and performance records. We have developed a multi-tier architecture integrating backend tools and systems with commodity interfaces. We implemented an asynchronous open information access environment supporting curriculum management, student databases, statistic data collection and presentation, assignment submission and performance evaluations, personalized data access on the web, securtiy issues, different user levels and access lists. The resulting environment, evolved with the needs, reached a large audience, more than 400 users, including in-campus and online distance courses, had used it. This paper presents a technical overview of the architecture and discusses its functionalities gained from the experience.
Recent technological innovations tremendously effected the education systems. Distance learning became a common technique in education. Technologies are adapted to many academic courses like the ones offered by Syracuse University to Jackson State students. In these courses, collaboration tools, mailing lists, bulletin boards are used, and rich set of online materials and reference links in WWW are presented to students.
Both synchronous and asynchronous techniques and resources are subject to continuous improvements. The computational science education group at the Northeast Parallel Architectures Center (NPAC) has developed a huge repository of online course material, which includes lectures, tutorials, and programming examples in various languages. To provide a regular basis synchronous interaction with students involving teachers and other learners, in addition to asynchronous learning materials, TANGO system was used to deliver CSC 499 over the Internet.
All these improvements in the technology based education methods bring new needs. Our education experience showed that the new face of learning has lack of online-open asyncronous information access environment both for students and teaching staff like registering, passwords assignments, automized mail lists, students' data recording, observing students, preparation and presentation of performance records, long term reference needs for a particular student work, assessment tools, which were used to be done by human interactions in traditional systems.
In a distributed environment, the system provides accesses from different locations through a complete security mechanism and user authentication interface integrated to commodity interfaces. Distributed students can on-line register for the courses. The student records and their performance records are planned to be kept in a database continuously that provides a base for a virtual university student services. A student can access his performance page, at any time from any where having web access; and/or can include his resume for the applications, which causes more reliable evaluations. Students may also use other services like post office, file uploading, class lists, submitting surveys, and other account administration.
Besides convenience at submitting the grades to the students, NPAC grading system helps to instructors as an assessment tool. The graders can see various statistics about the students at any time while grading from a web browser. A categorized questionaire database is useful for online surveys and quizes. Preparing class surveys provides keep tracking of the student progress, understanding course quality, and increased adaptability to the student needs. Possible customizations at the grading brings more flexibilities at the grading. In the system, additional to seing a simple grade, students themselves are able to see their performance, like average or expected grade, grader comments, and suggestions, etc., through the semester .
The environment also presents an user friendly administration interface on the web. A server administrator can tune up the performance and change the configurtion from any web-browser connected to the internet network.
The main functionalities in the environment as the collaboration of supervisors, instructor, co-instructors, TA, students, guests , and administrators through the Web Browsers are ;
Course Manipulations; add,update,delete, and surveys. Student Records Manipulations Assignment Records Manipulations Customizing Grading Preparing surveys Grading and Statistics System User Records; defining new users, manipulating user accesses System Services like backups, and class list construction Students' Access Menu, personal information and grades
With our experience we realized that especially the outside distributed students had lived diffuculties to follow a course presented with recent web technologies. Many students thousands miles away from our teaching center had frustrated to have offerings in-campus students had. A new complete integrated environment need to be presented to the outside registered students to make them feel like living in a virtual university. Even the in-campus students having many ascyncronous resources around craved such an environment.
Specific web-based interfaces should allow users to access certain information,perform related operations, and store the results in a statefull environment. For an example, on-line grading, or submitting student performance records was not so formal, secure, and flexible with email. Though individual solutions exists for long time, for examplesubmitting grades with pgp encyrpted emails, these techniques are not practical for every student and lack the completeness of an environment and future needs of students based on the sprit of the Web Education.
Not having the student records in a trustable, easely-securely accessible database environment is a complete disadvantage for both on and off-campuss students. The team offering the courses became loaded immediately by the work of technical class preparation. Construction of class lists, email lists, making unix accounts, listing student home pages, submitting passwords to students and keeping track with add-drop students, measuring class level with surveys for different types of courses needed many human-effort beacuse of lacking an automized environment. The issues like grading became problem in distributed education cases with respectful number of teaching team in charge. Furthermore, online progress tracking, having a categorized questionaire databank, automatically evaluation reports ,and similar services became a need more than a luxiary by the time.
Students themselves has private accounts with enhanced tools for their personal use, which they get by online registering to the courses. They can always see their performance records, use post office, upload homework files, administor their virtual directories and personal accounts.
The on-line grading provides an asyncrounous collobaration between distributed staff team members hided from the online students. Students may see their grades online, securly and privately after they are published by graders.
The grader has various altarnatives while grading. The grades may either be numeric grades, or customized grades like A, A-, B, B- , etc., or excellent, good fair, poor, etc., or present absent, in cases for k12 students. In either case, the average calculations can be done automatically. The grader may choose class list or individual assignments for faster grading. At any time, one can see the class averages, grade distribution, ranks, etc. The following pictures illustrates the usage of the system;
The grading interface contains information depending on the security level of accessing person. For example, a student can only see his grades, assignment ingormation, the points he lost or gained, and some comments by grader. On the other hand the grader can include some secret comments only available to the authorized people like instructors, or parents. Furthermore, an instructor or supervisor can also include top level secur comments for the individual grades or in general student performance which are only available for specific users. Grading Image URL http://carver.npac.syr.edu:3768/users-docs/msen7/paper/grading.gif
NPAC Virtual File Manager is integrated in the environment for uploading homework files into virtual directories in server side, and directory-file manipulations. Students uses the same passwords and/or transfered from their personal accounts to access their directories. File Manager Image URL : http://carver.npac.syr.edu:3768/users-docs/msen7/paper/filemanager.gif
In a similar fashion to surveys, class quizes can also be prepared. Beyond the regular quizes, different apects of quizes from student-self evaluation quizes to pop-quizes in class time are currently in progress.
The survey results are automatically evaluated and immediately presented to supervisors on their browsers. By using the surveys the understanding level and expectations of the class may be measured, and the performance of the class can be levaraged. An example of a class survey results are presented in the following picture; Survey Results Image URL http://carver.npac.syr.edu:3768/users-docs/msen7/paper/surveyresult.gif
The environment own services are also useful to tune-up the performance and to increase usabilty. The specific cache mechanism for user, student, course, assignment records leverage the performance by decreasing the number of database accesses. The connection mechanisms in the architecture can be controlled from a front-end interface to an easy use and configuration for administrators. The access logs, not only web access logs but the environment own access logs, are kept for future references and assessment.
The student records are one of the most private information in education.
Because of its exposure to the public over the internet, the whole environment is subject to attacks to capture, to alter, to destroy the private information. For the sake of completeness, complete security should be inseted into the architecture. We solved the security issues under the following categories; Security Image URL http://carver.npac.syr.edu:3768/users-docs/msen7/paper/security.gif
The architecture is a multi-tier architecture. In general it can be seen as a trhee-tier architecture. The more layers in middle tier especially designed in semantics of modularity and easy integration with other related projects.
The user interface completely presented as an commmodity interface. All the data access, and functionality is managed through the client browsers. The communication channel is secured with SSL to complete other inside security mechanisms as previously mentioned.
In the middle layer, the main intelligence of the environment is placed. The communication with the outside world is provided through the servlets. The middle tier itself contains different levels. The first level contains the high level functionalities to talk with the clients and to perform the operations in a more advanced level without considering the low level system dependencies like database connectivity. The relational database records are considered as the objects at this level. The second level mainly serves as a cache memory to database objects. The cache mechanism provided performance increases by decreasing accesses to the database for each operation. The objects in the cache are defined as the objects which are keeping single relational database table row entry and related methods to perform on them. At any time when a user login to his account, all of his personal records transfered to cache for any possible access by user, or the recent course records always kept in cache during the semester. The last level performs low level operations like connecting to the databases and performing database related operations. Each independent type of tables like, students, users, courses, etc., has an associated class. The table mapped class is responsible for accessing to database, fetching the records, turning them into objects, keeping the consistency with object modifications and database, and also related table operations like listing the whole table, sorting etc.
The last layer in the architecture is database backend. Since implementation is done with java, any suitable database supporting basic SQL standards can be choosen and the database access can be forwarded to selected database through JDBC bridge update in the front end options. In the implementation, SQL usage is minimized so that even some Databses like mSQL with full SQL standard support can be used.
The last layer also includes a template library stored as HTML-like files. The user interfaces can be easly enhanced simply by editing this HTML-like files without any knowledge of the java codes and database issues. The parser module takes this files and embed dadabase information into the HTML-like file and return a complete HTML file to the user dynamically.
The environment supports also the legacy systems through a cgi-module. One example is majordomo email list can be sent by instructors through a user interface which get the registered students from database. Any scripts can be added to the cgi module providing connection with legacy systems. Another example, using the same passwords for other support systems lunched by other groups.
The implementation is entirely written in Java in a portable fashion. Its layered and modular architecture provides easy upgrading and integrability with other environments, e.g., high level sharing database records. Other educational organisations like JSU also installed it. The environment provides easy server administratin and configuration additional to its convenience for users through the Web.