Given the transaction as a basic unit of analysis, a comprehensive model of value added roles can be distilled from the synthesis of network design and business process models. Any given implementation may be seen as a cluster of roles that add value for the buyer and produce revenue for the seller. The general representation of the model suggests that there are four common classes of roles fro...

The MIT Faculty has made this article openly available. Please share how this access benefits you. Your story matters. Abstract Microorganisms have evolved different systems for storing carbon during times of stress. In the cell's natural environment, the stored carbon can then be utilized for growth when other nutrients are in better supply. Storage of carbon and other nutrients is ubiquitous ...

can provide valuable information for evaluating and compensating teachers. Education researchers have recently recognized that easily quantifiable characteristics— including postgraduate education, experience, college quality, certification, and even scores on standardized tests—do not capture much of the variation in the quality of instruction as measured by the contribution to learning. This ...