234 H B. Chang, H H. Hsu, and L.R. Chao In the proposed interactive video game-based learning platform, the design concepts of adventure games are adopted to construct the game platform. The most important idea in adventure game is, the players find clues and try to solve problems by explor- ing a specified scenario and investigating objects there. According to this mode of game play, video is used for scenarios and the interactive objects provide players to get experience by examining and operating them. 3 System Architecture In the interactive VGBL platform, there are three major components need to be pro- vide to help design games and integrate educational materials with it. Interaction, knowledge delivering and rewarding should be included in the VGBL game authoring tool and runtime environment. 3.1 Interaction Design Interaction is the most import part of a video game. The interactions in games provide means to players to change states in game play. The players can get information from scenarios by making interactions and triggering events. There are different interac- tions and devices in various games. Without much difference from other adventure games, mouse and keyboard are responsible for delivering users’ interactions to the interactive VGBL runtime environment. Players can examine and move objects in a scenario by clicking or holding their mouse keys. Like ordinary adventure games, the players have a backpack to collect items in game. An inventory window is used for displaying what items the player owned. The players can get theses items from a scenario and use them in an adequate scene to trigger events. Interactive objects in video provide information to players. Users can get descriptions when they try to examine these items. There are also non player characters to give fixed conversation to guide players. 3.2 Relationship between Interaction and Knowledge Delivery The ultimate goal of game-based learning systems is to deliver knowledge to students. Actually, it is not easy to design games with educational materials. Course designers can produce scenarios by shooting videos and defining relationship between objects in it. By creating interactive objects and setting the events, the designers provide means to players and deliver knowledge in the process of solving a problem. For an example, in a classroom in game, the NPC told players a computer was not worked and order players to fix it. Players examine the computer in video first and find a broken com- ponent inside. Finally, players move to another scenario, markets, to get the compo- nents they needed and return to classroom and fix the computer. Students can obtain knowledge from the process of making decision and interac- tion. In the example, students get the instruction first, and then find the problem by investigating objects in game. Students will get different feedback after they install components into the computer by the content providers’ authoring. Interactive Video Game Platform for Game-Based Learning 235 3.3 Rewards to Users Rewarding for students is an important factor to motivate them to participant such games. Like general games, the rewarding mechanism is also applied in the platform. Players can get bonus if they make the right decisions which the content providers set in the authoring system. In this section, real rewarding is not discussed here because the lecturers will decide how to reward students themselves. In the interactive VGBL platform, some objects are considered as rewards. If players complete some requests or missions, they can get special objects in the inventory windows. Such objects differ from other interactive ones in scenarios; they represent the achievements which play- ers have. The courses designer can motivate players to collect such objects by provid- ing bonuses or other kinds of interaction. 4 Implementation We have implemented an authoring tool to generate interactive video games for edu- cational purposes. There are several subsystems implemented as follows: 4.1 Scenario Editor Designing a game is not easy task for general users. The scenario creation is one of the most challenging parts of designing games. We try to use video segments to Fig. 1. The interface of interactive VGBL authoring tool 236 H B. Chang, H H. Hsu, and L.R. Chao replace 3D scenarios because they are easy to produce. The users just need to select video files from network or video cameras such that video can be divided into sce- nario components by the authoring tool. Figure1 illustrated the interface of the interactive VGBL authoring tool. Courses designers can also insert objects like buttons and images in the authoring tool. 4.2 Object Editor The other important component of the authoring tools is the object editor. Image ob- jects are mounted on a video scenario. The interactive object plays an important role in the interactive video game-based learning system. The users can make interactions with theses interactive objects to trigger corresponding events. An object editor is implemented for such requirements. Users can set the properties and events of objects in video and produce adequate feedback when users’ trigger them. 4.3 Gaming Platform A runtime environment is also implemented for users to participant the games. The gaming platform is an augmented video player with the interaction functionalities. The users can manipulate the avatar in a game scenario and make interactions with the interactive objects. Fig. 2. An example of learning scenario Interactive Video Game Platform for Game-Based Learning 237 Interactive video technology is used to generate feedbacks to the users. By making corresponding interactions, the scenario changes and interactive objects pop out. With such environment, students would be interested in the contents and get concepts from the game play. Figure2 shows an example of learning scenario in library. Three image objects are mounted on the video frame. Players can examine theses books by clicking them or drag them to inventory window. In this learning scenario, users may be assigned a task to find an adequate book to be a reference for his homework. Users need to select one of these books to complete the assignment. In the library, user can access infor- mation of these books and drag the appropriate one to the actor bounded in the red box. 5 The Scenarios In this section, two scenarios are designed for evaluating the proposed platform with users’ experience. These two scenarios are described as follows: Interaction with keyboards and mice: It is composed of a video scene of an English tutorial TV program. This program is a little complex in its structure. There several parts like conversations, grammars expla- nation, vocabularies explanation and reviews. In this scenario, a user use keyboards and mice to access texts, images, web pages and video scenes with arranged hyper- links. Interaction with interactive objects: This scenario is different from last one mentioned above. A video scene for campus tutorial is presented to users. The scene begins at a building of campus. There is an actor in the scene and users can use different interactive objects to switch to next video scenes. Two interactive objects are presented in this video scene: baseball glove and basketball. If users drag and drop one of these interactive objects to actors, video scene switches will be triggered. For an example, if users choice the baseball glove, a video scene of baseball game with the actor will be presented. Otherwise, if the bas- ketball is selected, a scene with basketball game will be played after the beginning video scene. 6 Experimental Results A questionnaire with twenty questions for these four scenarios is used for evaluating the proposed platform. Every question in the questionnaire is an affirmative sentence. There are five options to user for every question: 5. strongly agree; 4. agree; 3. neu- tral; 2. disagree and 1. strongly disagree. All of these questions are listed below: Interaction with keyboards and mice: 1. It is convenient for using mice to select objects 2. Structural video courses help me to understand learning contents. 238 H B. Chang, H H. Hsu, and L.R. Chao 3. Accessing web pages by interactive objects helps me to understand learning contents. 4. Accessing images by interactive objects helps me to understand learning contents. 5. I am satisfied with time of switches between video scenes and other media. Interaction with interactive objects: 6. I can select objects what I am interested in easily. 7. The interactive objects of baseball glove and basketball are easy to under- stand. 8. Interactions by drag and drop are intuitional. 9. Web pages of campus help me to understand the campus. In a class of basic computer concepts, we have totally 111 students to answer questions listed above. Table 1 shows the distribution from the highest score to the lowest one. The row of AVG shows average for each score level of questions. The row of STDEV shows standard deviation for all score levels. Table 2 shows the same results with percentages. Table 3 shows the results with accumulated percentages. Table 1. Scores of questions score question 5 4 3 2 1 SUM Q1 28 51 21 6 3 109 Q2 11 67 27 4 0 109 Q3 9 54 42 4 0 109 Q4 14 58 31 5 1 109 Q5 8 50 36 13 2 109 Q6 20 49 27 9 4 109 Q7 15 52 28 10 4 109 Q8 18 42 40 8 1 109 Q9 14 60 25 9 1 109 AVG 15.22 53.67 30.78 7.56 1.78 STDEV 6.18 7.23 7.10 3.05 1.56 According to experimental results in the table3, the better parts and worse ones can be distinguished. We take option 4 as a threshold to determine which parts are satis- fied to users or not. In the third column of table3, percentages of users which select agree and strongly agree options are shown. The best two questions are Q1 and Q2. The results indicate users agree that the system is convenient and helpful. The worst . the computer. Students can obtain knowledge from the process of making decision and interac- tion. In the example, students get the instruction first, and then find the problem by investigating. can examine and move objects in a scenario by clicking or holding their mouse keys. Like ordinary adventure games, the players have a backpack to collect items in game. An inventory window is. a classroom in game, the NPC told players a computer was not worked and order players to fix it. Players examine the computer in video first and find a broken com- ponent inside. Finally, players