Ward Cunningham

A laboratory for teaching object oriented thinking

It is difficult to introduce both novice and experienced procedural programmers to the anthropomorphic perspective necessary for object-oriented design. We introduce CRC cards, which characterize objects by class name, responsibilities, and collaborators, as a way of giving learners a direct experience of objects. We have found this approach successful in teaching novice programmers the concepts of objects, and in introducing experienced programmers to complicated existing designs.

A diagram for object-oriented programs

We introduce a notation for diagramming the message sending dialogue that takes place between objects participating in an object-oriented computation. Our representation takes a global point of view which emphasizes the collaboration between objects implementing the behavior of individuals. We illustrate the diagrams usage with examples drawn from the Smalltalk-80™ virtual image. We also describe a mechanism for automatic construction of diagrams from Smalltalk code.

Using patterns to improve our architectural vision

Pattern languages can play an important role in furthering the use of architecture and objects in software design, but first we must understand what these terms mean. The authors use the work of Christopher Alexander (1975, 1979, 1981, 1985) to illuminate the problems and shed light on future directions in our use of pattern languages in design.

Designing reusable designs (panel session): experiences designing object-oriented frameworks

An object-oriented framework is a skeleton implementation of an application or application subsystem in a particular problem domain. It is composed of concrete and abstract classes and provides a model of interaction or collaboration among the instances of classes defined by the framework. A framework is used by configuring or connecting concrete classes and deriving new concrete classes from abstract ones provided in the framework. A framework is a reusable design because all users of a framework share its basic class structure and collaboration model.

Hacker or hero? - extreme programming today (panel session)

Extreme programming is the latest rage, everyone is talking extreme, but who is doing it? XP is in the words of one proponent, is a “lightweight, efficient, low-risk, predictable, scientific, and fun way to develop software”. XP bundles much conventional software engineering wisdom into a practice with a high degree of appeal as a cool technology. Questions for inquiring minds include: Will XP deliver? Will XP scale? How will products based on software developed by XP practices age? What are the elements of XP that can be effectively adopted by organizations outside the XP envelop, e.g. large teams, real-time systems, etc. Is XP the next “silver bullet”?

XP - Beyond Limitations?

As eXtreme Programming grows in popularity and acceptance within the software development community interesting questions arise on whether XP practices can be applied effectively beyond their assumed limitations. For example, as team size and system complexity increase - is XP automatically out of the picture or are there mechanisms now available to scale XP? Panelists will discuss and debate the threshold for XP suitability based on organization/ infrastructure characteristics, project complexity, team size, legacy issues and other relevant topics.