Previously I experienced projects that went nowhere simply because the team did not have one sense of direction or product vision in the first place.
This time we started with a series of kick-off meetings to lay down all assumptions and objectives as seen by each of us. Having experts from different domains on board allowed us to cover a lot of ground. For example, the following questions have occurred:
User perspective: Why do I need this learning tool? In what way is it helpful?
Education perspective: How do we make progress noticeable to the user?
Business perspective: Does this tool complement other learning solutions we own? Is there an overlay?
Development perspective: How do we keep audio playback in sync with screen-scroll? Is there a third-party dictionary we want to use?