XP customer practices: A grounded theory

The Customer is a critical role in XP, but almost all XP practices are presented for developers by developers. While XP calls for Real Customer Involvement, it does not explain what XP Customers should do, nor how they should do it. Using Grounded Theory, we discovered eight customer practices used by successful XP teams: Customer Boot Camp, Customer’s Apprentice, Customer Pairing, and Programmer’s Holiday support the well-being and effectiveness of customers; Programmer On-site and Road shows support team and organization interactions; and Big Picture Up Front and Re-calibration support Customers steering the whole project. By adopting these processes, XP Customers and teams can work faster and more sustainably

Physics, Topology, Logic and Computation: A Rosetta Stone

In physics, Feynman diagrams are used to reason about quantum processes. In the 1980s, it became clear that underlying these diagrams is a powerful analogy between quantum physics and topology: namely, a linear operator behaves very much like a "cobordism". Similar diagrams can be used to reason about logic, where they represent proofs, and computation, where they represent programs. With the rise of interest in quantum cryptography and quantum computation, it became clear that there is extensive network of analogies between physics, topology, logic and computation. In this expository paper, we make some of these analogies precise using the concept of "closed symmetric monoidal category". We assume no prior knowledge of category theory, proof theory or computer science.Comment: 73 pages, 8 encapsulated postscript figure

Concepts and their Use for Modelling Objects and References in Programming Languages

In the paper a new programming construct, called concept, is introduced. Concept is pair of two classes: a reference class and an object class. Instances of the reference classes are passed-by-value and are intended to represent objects. Instances of the object class are passed-by-reference. An approach to programming where concepts are used instead of classes is called concept-oriented programming (CoP). In CoP objects are represented and accessed indirectly by means of references. The structure of concepts describes a hierarchical space with a virtual address system. The paper describes this new approach to programming including such mechanisms as reference resolution, complex references, method interception, dual methods, life-cycle management inheritance and polymorphism.Comment: 43 pages. Related papers: http://conceptoriented.com