In my opinion, Serious Games will play very important role in the 21st century in order to extract knowledge. My opinion based on the following observations:

1. Educational level has dropped greatly in the world.

2. The big difference between the universities of America & Europe and Asia & Africa to get knowledge.

3. The huge and increasingly important role of modern Internet technologies.

Since this is an objective reality, I think that the future Education can be transformed to Self-Education. What is why I believe that Serious Games will play very important role. I believe that today's papers, books, monographs ... must be transformed to the Online Tools in the Internet. I believe too that each Online Tool must include a Serious Game in order to gain knowledge in an entertaining form. Thus, in my opinion, Serious Game should be highest stage in the process of knowledge representation in the 21st century. My very short resume is the following: Serious Game may be the most modern tool in the 21st to gain knowledge by the shortest way. Therefore my advice would be the following: Please creat and develop your own Serious Games as the Online Tools using modern Internet Technologies, e.g. ASP.NET and others. Please have a look at the discussion "Beside games, do you think virtual reality is useful for educational learning?" on the link

https://www.researchgate.net/post/Beside_games_do_you_think_virtual_reality_is_useful_for_educational_learning

I dont think so. The problem is that most of them are shaped on a very specific use case and will somehow get out of date or use quite soon. But there are some examples for very nice games that also work on long term like this: http://www.campaignpage.ca/sickkidsapp/ 

I think it depends but what I experienced is that if it is just for data collection (like to do object tracking or so) it does not survive long but if it helps to distribute and educate then is more durable.

Two studies done on the effectiveness of Operation ARA (a serious game that teaches scientific reasoning) have been over the course of a semester (4-5 months), but we have not done any longer than that yet.  Learning gains were found over that period of time, especially compared to the control group.  The manuscripts are in preparation.

Thank you everyone. I want to study serious game in this topic. The major problem I found is the engagement wore off over time. It should be some ways to sustain the level of engagement.

It's always hard to find studies that follow participants over a long period of time, because it's hard to run a study like this.

But only by logical thinking, one may conclude that it's hard to keep someone playing the same game over and over again, unless the game is capable of adding something new for the player over time. No one wants to do the same thing over and over game. Even with entertainment games, players usually play them for a time, after that they become bored and switch to another game. Unless the game is capable of adding new content over time.

For serious games, it is necessary to study what are the objectives of each specific game and consider if it's really desirable that the players keep playing the same game over time. For example, for learning games, specific games to teach specific knowledge would be better suited. After the student learned that piece of knowledge, they would eventually switch to other games to learn different things.

However, if you find a situation where keeping engagement with the same game over an extended period is necessary, employing extrinsic motivation, like external rewards, usually work for a brief period. The use of intrinsic motivation is necessary to keep engagement for a longer period. You can study about Self-Determination Theory to understand more about extrinsic and intrinsic motivation (http://www.selfdeterminationtheory.org/).

You can find extensive information about games and intrinsic motivation on the book "Glued to Games: How Video Games Draw Us In and Hold Us Spellbound" by Scott Rigby and Richard Ryan. They talk about games in general, but it's easy to understand that the same principles can be applied specifically to serious games.

Gustavo, thank you. I'll take a look at the book. For educational games, game's short life span is totally understandable. There is quite a problem for designing the game for health care. A health application requires patients to continue the medication and keeping track of their status for a long period of time. 

Not sure that those types of long term studies have been done...may want to check on the NSF website to see if any of the serious games that they have funded shown long-term gains.

Perhaps gamification is the answer. Serious Games are increasingly used for novel domains, such as elicitation of human behaviour in various situations (feel free to check my work on that, namely in evacuation scenarios). Another important aspect is training.

One research program to evaluate what you ask, is to have consistently workers to perform some kind of SG to train them in some aspect (working with a machine, safety procedures, etc.) and having them to repeat the game periodically to evaluate their evolution. That is something I have planed to do.

My 2 cents.

I think gamification can help to keep people playing. But I am not sure if that will lead to a long term commitment. Based on my own gaming experience I think that on a long term basis just the core fan base will keep playing (can be seen in a lot of successful games). I guess what could help is to give the game an additional function that the players also want to use in their daily live. For example a health tracker etc. Or provide new content in periodically intervals, as we can see in very successful games like World of Warcraft or Angry Birds, etc. Finally a good rule of dump is make it easy to learn and hard to master. That will keep people playing at least for a while and in a lot of serious games / gamification approaches this is already enough. 

@Fran, I'm excited to hear from your research.

@João, Have you planed how to evaluate the game in mind?

@Michael, interesting idea. In case of, we might not have enough resources to keep adding new contents like AngryBirds and WOW do, if there is some other way to by pass that. Do you think it is useful?

Gamification is an interesting path of study indeed. However, gamification research faces the same difficulty, as many of the published studies evaluated short term use. Initial studies seem to indicate that the combination of a well designed and useful application (one that is good at fulfilling a user need) with gameful design may indeed increase engagement with the application even for an extended periods. But we still need more studies to understand if this is true and how it works.

The attached publications include an example of a study that accompanied use of a gamified application for 2 years, and a study that included people who used Fitocracy for various different time frames.

Article Do badges increase user activity? A field experiment on effe...

Article Why do people use gamification services?

Gustavo, these papers are fantastic. Thank you.