Although it's not an article on DI, a recent feature in the Wall Street Journal titled "Practice Makes Perfect -- And Not Just for Jocks and Musicians" provides some good support of DI program practices, such as:

• You can be creative when you've mastered material: "Rote learning and conceptual thinking often feed synergistically on each other, freeing our brain capacity for those tasks that require the maximum amount of attention and creativity."
  
  
• The importance of the correction procedure: "...fast, simple feedback is almost always more effective at shaping behavior than is a more comprehensive response well after the fact."
  
  
• The value of practicing skills over time and introducing them systematically: "What drives mastery is encoding success - performing an action the right way over and over."
  
  
• Why the small-step design of DI programs is effective: "The brain likes to learn - but it prefers to in manageable leaps."

You can find the article here.