Welcome to the group, Andrew.
I agree that 'blue sky' (or ocean depending on your camp) thinking has its place, and incremental innovation works well in say humanitarian situations where the risk to life is too high.
But as Verganti (an engineer) suggests 'creativity' has its place in setting goals for incremental innovators to build bridges to.
2007 at the first ConnectEd Conference on Design Education held in Sydney, a keynote spoke on Bridge Design as incremental innovation, each new bridge a thinner, leaner design than the predecessor, some disasters have evolved from this cautious approach. Blue sky creatives would question the need for a bridge and suggest alternate transport.
So I still can't quite get what people find so hard about the 'C' word when brilliant minds like Amabile etal have dedicated their lives to its exploration.
I'm guessing that 'specific end' means achieving a desirable goal?
If so, it is that 'specific end' that make sense when you've got an issue/ problem to overcome or a need to address. I'm hoping that in future 'jams' we could introduce a problem as a 'design challenge' and a measurable outcome as a 'specific end'. In that sense, it would give us some constraint.
Albeit not the intention of the jam, I felt it was missing. Certainly missing from the majority of business analysts I've come across. Useful steps I think to frame ideas as propositions for customers: initial pitch, business model generation canvas, investment logic etc. I've found a step through guide on structuring the pitch in Jerry Weissmans 'power presentation' to be extremely useful.