ED-MEDIA 1999 Proceedings Book - Association for the ...

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DATABASE-DRIVEN WEB APPLICATIONS FOR TEACHING & LEARNING 1. Introduction Daniel Y. Lee Department of Economics & Coordinator, the Virtual University Shippensburg University Shippensburg, PA 17257 USA DYL@ship.edu Although many instructors now utilize the Web to supplement their courses, the Web pages they create are mostly “static” in nature. These HTML documents are written and then posted onto the Web server, where they sit until requested by a browser. Materials on these documents are outdated overtime until the Web developer revises them one page at a time, which requires considerable time and effort, especially as Web pages multiply. In the long run, a better strategy to maintain a Web site is to use “dynamic” pages linked to databases. These Web pages are "dynamic" in the sense that they are created “on the fly.” They don’t exist until a browser makes the request. Upon the information user’s request, the database inserts the requested information into preformatted HTML templates. If the information in the database is updated, the Web page will display the new information the next time it is requested by the user. The purpose of this paper is to provide an overview of how educational Web sites can be more easily administered, modified, and customized by using Web-database connectivity. 2. Developing Database-Driven Web 2.1 Advantages of using database-driven Web Web browsers provide a Graphical User Interface (GUI) that can be used to access many things, including a database. Unlike the traditional database management systems, the user would not have to configure and learn to program database client software. Instead, using a Web browser's built-in forms capability, users can access a database by simply filling in the data they want and pressing a button. The returned data can then be presented in an easily readable format. Furthermore, the Web's cross-platform support allows users on many different types of computers or platforms (Windows, Mac, Unix) to access a database from anywhere in the world. Information can be disseminated with a minimum of time and effort, without having to solve compatibility problems (Lee and Liu, 1998). There are several advantages of using database-driven Web development over the conventional “static” Web pages. First of all, Web pages can be created “on the fly” by querying current information stored in the database. New and fresh information can be presented to the user at each visit. This technology also makes it easier to administer, modify, update, and customize a Web site. In addition, users can tap into vast existing databases including many legacy systems through Web-database interaction. This allows for cross platform access without requiring custom client applications. Furthermore, database-driven Web makes it possible such useful functions as maintaining user state, i.e., user’s preferences and other user-specific information can be stored between visits for various uses. In addition to these benefits, database-driven Web renders particular advantages to educational Web sites. Databases are “an excellent way to manage the media components of a Web site … instructional Web sites comprise huge numbers of media objects and multiple of content creators; databases make managing this information and longer-term maintenance issues easier to address” (Ashenfelter 1998). 2.2 Mechanism of database-driven Web Typically, the Web server delivers a block of text written in the HTML to the browser, which parses the HTML and may request additional content, such as graphical data. The model works well for static data, but what about live data For example, how would a Web server deliver content that it generates based on user input One answer is to use a CGI (Common Gateway Interface) script to handle the database queries. CGI scripts are programs that let Web servers execute other programs and incorporate their output into HTML documents. The Web server executes a CGI program as a separate process to fulfill a user's request, which can be as simple as a Web page hit counter or as complex as a database query. Because a CGI program is external to the Web server, it can be written in virtually any language,
whether compiled or interpreted. Some Web servers provide libraries and interpreters for Java and Visual Basic for use by CGI programs. While CGI programs can handle basic Web-database connectivity functions, programming requires a steep learning curve. CGI programming is also subject to such limitations as input data validations and weak security. Recently various “middleware” products have been developed to minimize the CGI programming time and additional features of Web-database connectivity, including superior security, input data validation, e-mail protocol, etc. Middleware is a general term for any programming that serves to glue together or enhance two separate programs. Users now can create Web-database applications by using a fourth generation language middleware products such as Cold Fusion or Active Server Pages. Database-driven Web publishing involves three major components: the Web forms, CGI or middleware, and database system. The mechanisms for Web-database interaction are shown schematically in Figure 1. There are four major stages in this interaction. First, the user fills the Web form using the browser, requesting pertinent information. The browser submits the request to the Web server. Second, the server invokes middleware or CGI scripts, accessing and querying the database. Third, the middleware or CGI retrieves or produces a HTML document. Finally, the Web server sends the result to the browser for display. CGI script or middleware makes it possible for the operations such as opening and updating appropriate database tables to link form objects to a database structure specified in the database design. The Web server and database server can be hosted in a single computer or two separate machines connected through the Internet. 2.3 Design of a database-driven Web To design an effective database-driven Web, three major design activities must be performed, including Web form design, database development and CGI or middleware programming. Web forms are necessary as a user interface for a database-driven Web. The information user can send a request to a database by submitting it via Web form. A relational database is composed of rows (for records) and columns (for fields) in table format. Compared with a flat file structure, database approach has the advantages of minimal data redundancy, information sharing, and data consistency. Finally, some programming is required to connect the Web forms and databases. For example, Active Server Pages utilize extensively Visual Basic programming knowledge. Visual InterDev utilizes more user-friendly graphical interface. Cold Fusion eliminates some of the complex CGI coding by combining standard HTML with a server-side markup language called the Cold Fusion Markup Language (CFML). For example, the CFML tag can replace many lines of CGI programming codes. In addition, Cold Fusion supports such advanced features as security integration, dynamic Java forms, data entry valuation, e-mail integration, Lightweight Directory Access Protocol (LDAP) support, and advanced SQL (Structural Query Language).
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Designing an Interactive Learning E
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develop an educationally meaningful
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2. Functionality of the BSCW System
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3. First empirical findings During
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of the users as participating actor
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2. Other Characteristics of the Pro
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education resources are being produ
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y using a drop-down menu: Informati
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Results Computing ability and expos
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instructional designs while introdu
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Global Educational Multimedia Serve
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Assured Access/Mobile Computing Ini
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The University has set up a secure
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* Changes in educational paradigms
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Using Computer Imagery and Visualis
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Publishing an imej Journal for Comp
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In summary, we offer the following
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Discussion Forums and Peer Review F
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Languages and Statistics: Solutions
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Kelly and Leckbee (1998) indicate,
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A Wide Array of Uses: Inquiry and I
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Effects of Question-Based Learning
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The EFFECTS of TRAINGING METHOD on
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3. RESEARCH METHODOLOGY A 10-day ex
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prototype for futuristic learning e
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Designing a Course Web-Site to Supp
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International Collaborative Learnin
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Facilitation frameworks Bostrom et
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From table 2 it can be seen that te
Page 59 and 60: Learning in Safety and Comfort: Tow
Page 61 and 62: Networking The Nation Noel Craske S
Page 63 and 64: Norfolk Stations. Schools of Distan
Page 65 and 66: one-on-one with Teaching Assistants
Page 67 and 68: Java. One of them is already an exp
Page 69 and 70: • Personal study room management
Page 71 and 72: As has already been discussed in th
Page 73 and 74: On-line Support of On-Campus Educat
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Page 77 and 78: How the Construction & Analysis of
Page 79 and 80: Yet, still we ask ourselves: How do
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Page 83 and 84: A Reporting Simulation Using Toolbo
Page 85 and 86: environment — it is impossible to
Page 87 and 88: Actually, when a particular author
Page 89 and 90: Any instance of this type is an HC
Page 91 and 92: Figure 5: Saving an Educational App
Page 93 and 94: To address this problem Webfuse dra
Page 95 and 96: Cognitive tools can act as structur
Page 97 and 98: In this study, we propose the follo
Page 99 and 100: more information about it, for exam
Page 101 and 102: Charlottesville, VA., 691-696. Muly
Page 103 and 104: ownership is retained by the instit
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Page 107 and 108: limitations of the prevailing compl
Page 109: exchange information with other cla
Page 113 and 114: A web site system for instructors t
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Page 117 and 118: the capability grant G13 as Not Set
Page 119 and 120: Slavin R.(1994), Small group method
Page 121 and 122: tutor. Support offered in the form
Page 123 and 124: Apart from utilising the functional
Page 125 and 126: Rogoff, B., & Lave, J. (Ed.). (1984
Page 127 and 128: Java can significantly increase the
Page 129 and 130: The modules are designed for a vari
Page 131 and 132: adapted tests to assess the student
Page 133 and 134: Architecture of HEZINET The system
Page 135 and 136: Berners-Lee, T. & R. Cailliau, (198
Page 137 and 138: The ParlEuNet system will provide a
Page 139 and 140: 3. Students use a dedicated HTML co
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Page 151 and 152: Streaming 7000 films... Uwe Sander
Page 153 and 154: and how to innovate will be paramou
Page 155 and 156: Toward a framework for instruction
Page 157 and 158: A knowledge integration approach to
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comparisons to conventional instruc
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Multimedia Cases in Teacher Educati
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Merseth, K.K. (1996). Cases and cas
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Using Multimedia to support mentors
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Conclusion The project is still und
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An Investigation into Faculty Attit
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Web-Based Testing in Distance Educa
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Selecting Internet Technologies to
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Designing and Implementing Web-Base
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