Quests in video games are a nice way to give players choices to make and offer a story line that seems a bit less linear. Have you noticed, though, that most quests seem to follow the same pattern? Usually, they're all about picking up a certain number of items or killing a certain number of enemies. They tend to be a list of tasks to complete rather than offering an overall goal that could met in a variety of ways.
Anne Sullivan, a recent Ph.D. graduate from UC Santa Cruz, spent at least some of her years as a grad student working toward making quests more interesting. She calls goal-based quests playable because they offer players meaningful choices in terms of how the quests are completed.
In her framework, Anne focuses on the use of social (as opposed to attack-based) mechanics. Players are able to complete social-oriented quests that are dynamically selected by the framework. What quests are available is partially based on what plot points in the overall game narrative the player has seen so far. The quests are goal based, so players can decide for themselves how they would like to complete them.
For example, if the quest involves breaking up a dating couple, the player might be able to get one person to distrust the other, or start dating one him or herself. Or, he/she might even cause the opposite to happen and encourage the couple to elope! The overall game story may change based on what the player chooses to do — something you rarely see happen with quests these days!
I really like this concept, not only for the new type of social mechanics (fighting gets old for me), but because the quests actually affect the rest of the game's story. This does occur in small ways now, but the main plot points hardly change if ever.
I also noticed in Anne's publications some similarities between what I read way back when in Chris Crawford's book on interactive storytelling and the structures used to capture the social mechanics in her own framework. I didn't follow the citations back to see if the framework (and what it was built on) was directly inspired by Crawford, but it does make me a little bit happy to potentially see Crawford's work becoming useful considering this sad article about him.
I am likely to do work in the area of quests and non-linear story, so hopefully I'll also be able to help make a difference in the quest to make stories more playable!