## 3 Presentation to the Participants
### Computers, Game Consoles and Mobile Devices  
Most serious games designed for children with ASD are delivered via conventional computers (such as desktop or laptop computers) or mobile devices [12]. The visual content can be displayed on a laptop screen, a computer monitor, a TV screen, or a touch screen from a mobile device. An advantage of using a mobile device to deliver a game/program to a participant is the convenience [13; 14; 15; 16; 17]. A participant could play the game or engage in a program anytime he/she wants and virtually in any posture. Virtually all mobile devices and some newer computers (especially laptop computers) are equipped with touch screens, which enable users to make their choices directly on the screen instead of via a keyboard and mouse [18]. Some of the games designed to run on mobile devices [14] such as iPad, were adapted from traditional assistive tools used for ASD training, such as the cognitive affective training Kit ([[http://www.cat-kit.com/](http://www.cat-kit.com/)]([http://www.cat-kit.com/](http://www.cat-kit.com/))). Figure 3: Three major delivery forms of technology-facilitated autism studies. Some serious games involve avatars or a combination of avatars and pictures/videos of real people for various purposes such as the understanding emotions as well as recognition of different emotions via facial expression and body gestures [19]. Another interesting trend in serious games is development of collaborative virtual environment where users can collaborate and communicate during games [15; 20; 21]. In recent years, motion-based touchless serious games can be played using game consoles (selected from commercial games appropriate for children with ASD) [22; 23; 24], or via computer systems [25]. Different from traditional serious games, this type of games engage the full body movements of the participants. In addition to traditional learning targets such as social skills and attention skills, this type of games could enhance motor skills of children with ASD. On the opposite end is a notion of tangible user interface where a user can directly touch physical objects, such as LEGOs. It is touted that the combination of tangible user interface and the computer-based graphical user interface will lead to more effective education/treatment for children with ASD [26]. Design guidelines for serious games for children with ASD were laid out in [25]. Even though it was introduced in the context of motion-based touchless games, they appear to be applicable for all serious games. In [27], [PERSON] et al. also provided a set of design principles for serious games. The guidelines include the following key points:  
* Strong customizability. The game must be customizable to fit the needs and preferences of each child with autism. Unlike many diseases, autism children may have drastically different strengths and skill deficiencies. * Increasing levels of complexity of game tasks. As a child acquires more skills, progressively more challenging tasks should be made available. This is the case for virtually all serious games. For example, [PERSON] et al. [14] reported the development of an iPad-based game for children with ASD to learn emotion recognition. At the highest level, there are three worlds. There are six difficulty levels within each world. Each scenario contains one scenario depicted by a video of a human actor. At the end of the video, the headshot of the actor with a facial expression appropriate for the scenario is shown and the participant is asked to identify the emotion expressed by the headshot. * Clear and easy to understand task goals. For each task, there should be a clear goal that can be easily understand by the participant. * Multiple means of communicating game instructions, such as text, voice, and visual cues. Some children with low functioning ASD would need visual cues in particular. * Positive reinforcement with rewards. Game score alone might not be enough to motivate children with ASD.