A new Wired Science article says using a framework or a form to work within increases creativity.
The experiments are discussed here:http://www.wired.com/wiredscience/2011/11/need-to-create-get-a-constraint/
The article has this to say: "The larger lesson is that the brain is a neural tangle of near infinite possibility, which means that it spends a lot of time and energy choosing what not to notice. As a result, creativity is traded away for efficiency; we think in literal prose, not symbolist poetry. And this is why constraints are so important: It’s not until we encounter an unexpected hindrance – a challenge we can’t easily resolve – that the chains of cognition are loosened, giving us newfound access to the weird connections simmering in the unconscious."
...More evidence that it's bumping up against the supposed obstacles that opens up my mind and nudges me toward a clearer picture of reality.
There is wisdom in working within the structure of the practice.