(Levin & Waugh. 1997; Nakahara et al. ..... [12] W. Richard Stevens, (1994), âTCP/IP Illustrated, Volume 1: The Protocolsâ, Addison-Wesley Publishing. Company.
Development and Evaluation of an Electronic Bulletin Board System Visualizing User Interaction SATO, Kouki* YOKOYAMA, Setsuo** AKAHORI, Kanji* *Dept. of Human System Science, Graduate School of Decision Sciences and Technology, Tokyo Institute of Technology, Japan **Computing and Networking Center, Tokyo Gakugei University, Japan
Abstruct Today, many electronic Bulletin Board Systems (BBS) are established on the Internet and have been used in many researches of Computer Supported Collaborative Learning (CSCL). And then, in this study, (1) the authors picked up and identified necessary functions and interfaces to exchange ideas. And then (2) the authors developed and evaluated a new electronic Bulletin Board System including the functions and the interfaces described above. In part (1), the authors carried out a research using standard Bulletin Board System displaying time-series. Accordingly, it was identified the necessity for displaying the relation between writings and visualizing user's impression and popularity of the writing. In part (2), the authors developed a system based on the above results. This system displays the writing connection using 3D-tree-structure. In addition, it can visualize the user’s impression and popularity using color variation. Then the authors carried out an experiment for the evaluation of this system. It was cleared that visualizing interactions are effective in interchanging ideas. But there is room for improvement in the method of visualizing and user-friendly operationally of this system.
Keyword: BBS, 3D-tree-structure, Visualization, Interface, Interaction, CSCL, Internet
1. Introduction Today, many electronic Bulletin Board Systems are established on the Internet. Many of them are made by CGI on World Wide Web (WWW) pages. And these are used for communication and exchange of ideas between general public. The authors call the standard electronic Bulletin Board System as BBS in this paper. The BBS has the following characteristics: (1) this is not limited by time and place, (2) writings preserve, (3) more than one person can access at the same time. Therefore, the BBS is useful for collaborative learning. Recently, many researchers work on CSCL: Computer Supported Collaborative Learning. (Levin & Waugh 1997; Nakahara et al. 2000; Riel & Levin 1990) And they use the BBS in their studies. (For example, Ishii 2000) In this study, the authors focus on exchange of ideas in the new BBS better than in the existing BBS. For that purpose, the authors picked up and identified necessary functions and interfaces, and the authors developed and evaluated a new electronic Bulletin Board System including the functions and the interfaces described above.
2. Pilot Research for Effective Functions and Interfaces 2.1. Objectives The objectives of this pilot research are to explore and verify effective functions and interfaces for good exchange of ideas. Using the result derived from this research, the authors develop a new BBS. If effective functions and interfaces are picked up from the existing BBS, the authors expand and include them. If problems are identified and new functions are necessary, the authors include them.
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2.2. Method Subjects are about 60 university students. They have not used the existing BBS so much, but they have the capability of basic PC operations. The authors select the subjects because they would be able to draw a comparison between exchange of ideas in the BBS and face-to-face discussion. (Their literacy and history of using PC, Internet and BBS are demonstrated in Table 1 of the next section.) The subjects interchange ideas and discussion to use an existing standard BBS displaying time-series. Figure 1 shows overview and main display of the BBS. It has very minimum set of necessary functions because the authors would like to explore more effective functions and identify them more clearly. Write response message to target one
Title
Author Name and Time Write new message Message
Figure 1: Standard Time-series BBS for the Research (in Japanese) The theme of the discussion is “the brutal crimes by teenagers ”. The research is carried out in the university classes. The subjects are divided into 3 classes in 5 groups (1A, 1B, 2A, 2B and 3). At first in one class, the authors send out a questionnaire about subjects’ computer literacy (Table 1). Second, the authors explain about existing BBS and how to use the BBS in brief. Then, the subjects discuss and interchange ideas about mentioned theme in the BBS for 50 minutes. Logs of the discussion are recorded into the BBS database. In the end, the authors send out a questionnaire about the discussion and the BBS.
2.3. Result Table 1 shows the results of the questionnaire before the discussion. Topics
Unit of Data 1A
Data of Each Group 1B 2A 2B
(1 to 5 scale rating 2.37 2.34 with 1 being lowest) Time of using Internet during a week Hour 2.52 1.67 (1 to 5 scale rating Typing speed 3.20 3.44 with 1 being lowest) “Have you ever used the BBS?” Percentage of “Yes” 27.3 11.1 (1 to 5 scale rating “How often do you use the BBS?” 2.67 2.00 with 1 being lowest) Table 1: Results of the Questionnaire in Each Group Self-confidence in using PC
Ave. 3
2.00
2.28
3.00
2.31
1.73
3.55
7.17
2.90
2.67
3.00
3.17
3.04
20.0
0
100
25.0
1.00
-
2.83
2.31
In all groups, the discussion was so exciting that subjects write to BBS after the experiments. Some of the subjects could not use the "reload button" in the web browser, so display became old and the subject became confused about the discussion. And they were also bewildered by supplementary writings. From subjects’ comments in the questionnaire after the discussion, exchange of ideas in the BBS is very joyful and exciting. They were easy to make remarks compared to face-to-face discussion. But connections between writings were not clear. And they wanted to know how others think about the writing and how many other users read the writing.
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2.4. Consideration The authors describe following considerations from the research about 2 topics: (1) the good interface of BBS to interchange idea, and (2) the effective functions in BBS. 2.4.1.
About the good interface of BBS to interchange ideas
For the comments in the questionnaire after the discussion, many remarked about weak points of time -series BBS. For example, “I had trouble seeing writings that went to under the BBS page” and “Connections between response and original writing were not clear”. In this consequence, it was cleared that necessity of displaying writings as much as possible on one screen and visualizing connections between the writings. And then, there were remarks describing about weak points of the web browser. For example, “it had been useful to make reference to writings when I wrote a new message”. 2.4.2.
About the effective functions in BBS
For the comments in the questionnaire after the discussion, it was mentioned that the connections between the writings were unclear. For example, “It is effective that the response of a writing had been more comprehensible”. And conversely, “seeing original writings of a response writing are effective”. There were some expectations to show more of the writings on one screen. In the web browser, the BBS had the problem that the user has to click the “reload” button at regular periods. It was clear that the function to reload writings automatically is necessary. As compared to face-to-face discussion, there were good few comments that it was easy to write objections. And they understood outline and the flow of the discussion more easily. On the other hand, the users were anxious to know how did others think about their writings. About the first advantageous case, it is more effective to display the flow of discussion more clearly. About the second unfavorable case, it is necessary to present others impressions about the writing to the anxious users.
3. Development of the System The authors developed a new electronic Bulletin Board System including good interfaces and effective functions from the above results. Figure 2 introduces overview of the system, shows the main display and exposition about the functions.
Menu Bar: The user can write a new message and redraw writings.
Red node: Favorably Impressed Writing
Dark node: Not Popular Writing
Blue node: Unfavorably Impressed Writing
The system can display writings 3D-tree-structured and redraw automatically.
Status Bar: When the user overlaps a mouse cursor on a writing node, this display the message title and author. Figure 2: Main Display of the System
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The system was named “3D-BBS System” and developed by using Microsoft Visual Basic for client part, Active Server Page for server part, and SQL Server for database. Figure 3 shows the system configuration when the user reads writings and writes a new message. Server Part
Server Part
Client Part
ASP for Reading
HTTP(GET)
ADO Writing Data ODBC (XML Format)
ASP for Writing
Displaying
Client Part HTTP(POST)
Result (XML Format) Writing
Figure 3: System Configuration of Reading (Left) and Writing (Right) In the following, the authors explain devices and functions of the system. (1) 3D-tree-structured display of writings based on visualizing “idea forest” metaphor The authors apply the relations between the parent and the child in “idea forest” metaphor (Choui et al. 1997) to the connections between the response and the original writing. And the connections of writings can be visualized in a 3D-tree-structured display clearly. And the writings displayed in one screen are increased by 3D-tree-structured display, too. So it is effective as compared to existing 2D-tree-structured BBS to look through the writings. Figure 4 shows this overview mechanism. Similar to the system, there is a previous study on visualizing information to 3D display. (Card 1996; Sheelagh et al. 1995; Shiozawa et al. 1996; Shiozawa & Matsushita 1997)
Shorter space Too large space
Figure 4: Displaying 2D-tree-structured (Left) and 3D-tree-structured (Right) (2) “ Unravel-reading” the raveled response writings In this 3D-tree-structured display, it becomes jumbler as response writings are increased. In this system, users can unravel response writings according to “rotate” of the child writing nodes. And users can read response writings easier. Figure 5 shows the appearance of rotating the child writing nodes. (A) (A) (B)
(C)
(C)
(B) Figure 5: Rotating Writing Nodes
(3) More effective screen scrolling than existing scroll bar The users usually view existing BBS on a web browser. So if they can’t view all contents of web pages, they need to move the mouse to existing scroll bar and scroll the screen. The authors developed a system that enables the users to scroll screen by dragging mouse. Figure 6 shows the appearance of scrolling the display by dragging mouse. (4) Updating writings of display automatically Periodically, the client computer automatically connects to sever computer and downloads the current contents of writing data. Automatically the screen is redraw, but the position of user viewing does not change.
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(5) The user can refer to certain writings while viewing another writings The user can refer to certain writings when viewing another writings such that writings are displayed in another window. This is showed in Figure 7. Main Display
Figure 6: Scrolling Display
Sub Window
Figure 7: Referring another writings
(6) The users can vote for writings of others about their impression The users can vote for other writings about their impressions (4 scale) by using “the impression icon”. Table 2 shows the 4 scales of impression icons. The Impression Icon Meaning of the Icon Impression Impression Point
(^o^)/ (^-^) (-_-;) All for the suggestion Agreement Some doubt Agreeable +2 +1 -1 Table 2: The Impression Icon
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