# A New Measure for Serious Games Evaluation: Gaming Educational Balanced (GEB) Model
## 2 Materials and Methods
### Motivational Design
Regarding this issue, various authors [47; 76; 77] support focusing the realist graphics, sounds and dynamics on the learning contents to prevent any distraction. Realist aspects also involve stimulating a desire in the player to create a personal avatar [67; 68] as a reflection of themselves [78]. It reinforces the user's sense of relevance in the game and immersive learning [79]. Although customization may be difficult to integrate in the development of a game, one advisable option is to offer a range of eligible characters with different appearances [3]. Another concern is the engagement with Non-Player Characters (NPC). The way the NPCs communicate and play different roles will affect the user's attention. Rather than textual dialogues, players prefer voice dialogues that introduce a heightened sense of realism [80]. People are accustomed to instructions communicated through intonation and facial expressions [81]. Therefore, user engagement is encouraged by showing NPC emotions and communicating through natural language and voice instead of text [23]. * AI and Adaptivity  
Artificial Intelligence (AI) will adapt the game to the player's actions [3] through its agents both in an immediate and in a goal-directed way [82]. Adaptivity responds to the user's profile [83; 84] and activity that is tracked and recorded on a database, activating programmatic flags to adapt to the choices [85]. This aspect is essential to guide players through the game and make the learning more effective [86; 87; 88]. The least intrusive adaptation is to use NPCs to provide the necessary feedback [76], so that the immersive experience will not decrease. Moreover, the sense of enjoyment is greater when these reactions turn out to be natural and customized [23; 89]. Another aspect is the difficulty of adaptation that depends on the player's ability to avoid any frustration [90]. Once again, the development possibilities must be taken into account [91], nonetheless some multi-choice gameplay variations should be offered [92]. * Interaction  
Playing games is based on Interaction. Players perform an action and the game responds accordingly through the audiovisual interface, instigating the next action. Complicated interfaces that frustrate players [72; 93] and induce additional cognitive load [55; 94] are not appropriate for serious games [79]. In various studies, it has been shown that the mechanics controlling the interface should be as direct and easy to learn as possible [52; 85; 95; 96]. In this way, the interface should easily show both the status and the tools that are needed to progress and learn from the game [97]. Moreover, different experiences show that the game should include a tutorial level so that players can learn to handle the interface [67; 81; 98; 99]. Subsequently, the game should progressively complicate the interactions [65; 71] to challenge player skill levels [100]. In addition, collaborative playing through player interaction leads to successful learning. Sharing tactics and solutions to solve conflicts can also increase learning. This exchange can be implemented through chatsand voice communication, unless the application is impossible, in which case the sharing may take place during the debriefing [3]. * Feedback and Debriefing Feedback is presented in two different ways. First, within the game through the NPC interactions and reward mechanics which produce an immediate cause-effect response [25,70,80]. The player experiences progress through these exchanges and becomes more competitive, wishing to unlock more content [72,83,101,102]. In the inclusion of feedback, it is important to consider the target audience to which the serious game is directed. If among these there are people with disabilities or special needs, designers must adapt games and learning content for them [103]. Second, the context in which the game is played is relevant, since it accepts the possibilities of feedback [104]. Real-time teacher support should be introduced, to enhance in-game feedback [105].