Let’s start with a little bit of history. The Boy Scouts and Girl Scouts were the first to "invent" badges in first part of the last century. In the 1980’s, the game industry reinvented the badge system, which went by the name “leveling”. In the early 2000's the game industry adopted an "achievement" system, a digital version of a Boy Scout merit badge. In 2009, Mozilla took the achievement idea from the game companies, re-coined the term "badge" and used it for educational purposes.
Given this history, it should be clear that badges mean different things to different people. Mozilla makes a useful distinction between the three badge types:
• Skill badges- These are the Boy Scout merit badges and what the game industry calls "achievements." This is what I find most people mean by badges. Skill badges certify expertise in a topic. These badges tend to be a bit more extrinsic of a reward than stealth badges, and in my experience are motivating, but not as motivating as a good intrinsic stealth badge structure.
• Stealth badges- These are what the gaming industry calls "leveling" and the Boy Scouts call “ranks”. Stealth badges typically relate to general status. The game industry often ties your level to unlocking content, meaning more status equals access to more interesting stuff. This creates an intrinsic reward structure, which creates much of the inherent motivation present in games. If badges are supposed to be motivating, in my experience I’ve found stealth badges to be far and ahead the most motivating type.
• Community badges- These badges are really a result of the social media world. Community badges are given socially, often for social skills like teamwork. In a sense, they are simply skill badges that are judged by peers rather than teachers.
These categories are not mutually exclusive. For example, the Khan Academy uses a hybrid stealth/skill badge structure- badges are related to certain skills, but they build upon each other in a sort of leveling system. Gaining lower level skills "soft-unlocks" access to higher badges. This sort of tree network of badges has been employed by several games, to great success (the job system in several Final Fantasy games or the creature collection portfolio in Pokemon and Dragon Warrior Monsters). If you can find a way to utilize this hybrid tree, it not only gives great feedback on progress and allows clear goals to be set, but is also partly for these reasons highly motivating.
We can learn a lot from the stealth badge system, because I think this is what games do exceptionally well, but educators have done relatively poorly. Leveling systems in games are almost always linked to unlocking features in a game. The newly unlocked features typically make you better at the game, which allow you to gain even more levels, which unlocks more stuff, which allows you to play the game better, which allows you to gain more levels, etc. It is a viciously addictive cycle that is highly motivating. If you haven't experienced it, pick up Pokemon or Harvest Moon and experience the psychological power of an intrinsic reward structure.
Unlocking Structures: Take it to the Next LevelThere are two types of these unlocking structures in games, what I call hard-unlocking and soft-unlocking. In hard-unlocking structures, there are typically discrete levels, and once a level is gained, a discrete feature is unlocked. There may be an area of the map you just can't access until you reach level five, or there's a difficult activity you can't do until you complete three other activities. In an education game there could be a tutorial that you are not allowed to access until you complete a previous tutorial.
In contrast, in soft-unlocking there is nothing actually restricting you from accessing higher content except your own skill. You may be free to access a certain part of the map, but you will probably lose if you go there until you reach about level five. Or you can do a difficult activity at any time, but you are unlikely to be successful at it until you gain experience with three other easier activities first. Or you can watch a tutorial at any time, but are unlikely to understand it until you have watched previous tutorials.
Hard unlocking structures tend to feel more forced and unnatural, but can also direct focus and create well-ordered problem solving. Typically, gamers consider soft-unlocking structures more elegant, but they are also more difficult to design. Soft-unlocks allow users to continually challenge themselves, more readily leading to the optimal experience of flow. Soft unlocks also allow more choice and can be less frustrating for an advanced player, who is free to skip ahead to later content if wanted. I also think soft unlocks give a greater feeling of accomplishment- being able to do something at any point in time means that the only thing stopping you from achieving that badge is your own ability. Once you gain it, you can really feel your own progress. In a hard unlock, it less clear that your own ability led to your success, since you weren't able to access the challenge initially.
I hope this provides some clarification on what badges are and how they have been used in non-educational environments. Now for the real question- what types of badges should be used in education and in what ways?