A talk by David Kirsh at a conference in lyon, France: Cost Structure and the Design of Environments : Design Lessons from Starbucks, watching TV and Microwave Ovens:

I present a micro-analysis of espresso making at Starbucks, watching TV and using microwave ovens to show difficulties with the cost function approach to design. An intuitive idea, discussed originally by Herbert Simon but pursued by many, is that the artifacts, technology, and resources in a setting define a cost structure for the activities performed there. This cost structure is the result of applying a cost function to each task-relevant action at each task-relevant state that can occur in that setting. The role of technology and design is to reshape the setting in a way that restructures the costs and benefits of actions so that more efficient routines emerge. The result is that tasks can be performed more easily and quickly.

I show why this model is seductive by looking at how the activity of watching TV has changed over time. I then look at the realities of activity in Starbucks to show that there are more factors determining effective routines, and hence good design, than those mentioned in cost functions. I also look at the remarkable design world of microwave ovens and related kitchen appliances to show that the dynamics shaping design are more complicated than standard efforts at formalizing accommodate. We need additional concepts to understand the dynamics of design

One can also find here what Kish values in Starbucks cups:

Thus, the marks on the paper cups used in Starbucks coffee houses, carry a special meaning to the staff. They are a code that has to be learned. Such marks are worth studying because they are an instance of a trick which, at one time, only the most experienced coffee making staff practiced. Yet now they have been institutionalized in workflow so that in rush hour all cashiers specify drinks in an unambiguous code that compensates for interruptions, noise and memory limitations on the production side. To understand how annotations help workflow we need to undertake a variety of careful studies in everyday venues.

Why do I blog this? because I like Kirsh's approach to distributed cognition.