claim: "computational media - the ultimate thing that make us smart"

- question: why?

- question: how?

- examples: ?????

framework from Norman:

- creating representations

- experiental <----> reflective

- hard <----> soft technology

- knowledge in the head <----> knowledge in the world

examples:

- spelling corrector

- critiquing ---> embedded critiquing

- OAG --> different views computed dynamically

general dimensions:

- mimicking, emulating versus complementing

- "gift-wrapping" and "rear view mirror"

--------X----------------------------------------X----------------------------> time

design time use time

exploit the context which is only

available at use time

Software Design <----> Software Engineering

sotware engineering:

- inward-looking perspective

- a piece of software works ---> means: it is robust, reliable, and meets its functional specification

software design:

- outward-looking perspective

- a piece of software works ---> means: it works for people in a context of values and needs, produces quality results and a satisfying experience

although there is a huge diversity among design disciplines, we can find common concerns and principles that are applicable to the design of any object, whether it is a poster, a household appliance, or a housing development

software design is a user-oriented field, and as such will always have the human openness of disciplines such as architecture and graphic design, rather than the hard-edged formulaic certainty of engineering design

what is software design?

1. how does it differ from programming, software engineering, software architecture, human factors and interface design?

2. how is it related to other fields that call themselves design, such as industrial design, graphic design, information design, urban design, and even fashion design?

a fundamental principle: "Complex systems will evolve from simple systems much more rapidly if there are stable intermediate forms than if there are not." (Simon)

experience with software reuse in the past:

- reuse does not work as expected

- reuse is not for free

- reuse requires support tools (e.g., for capturing design rationale)

- object-oriented design may be necessary, but is not sufficient

reuse is not only a technical problem:

- design for reuse --> increases up-front costs

- reuse requires an organizational commitment

the human mind is limited

- there is only so much we can remember

- there is only so much we can learn

information overload (browsing does not scale up and search with keywords is of limited use)

motivation

- what will make workers want to share? ----> community knowledge bases, distributed memories

- who is the beneficiary and who has to do the work? ----> organizational rewards

- what will make learners want to learn? ----> making information relevant to the task at hand

empirical study: McGuckin Hardware in Boulder, Colorado - more than 350,000 different line items

- problem framing and problem solving are intertwined (from heat generation to heat containment)

- to determine the adequacy/relevance of a found object requires "simulation of use situation" (the plumber story)

empirical finding: "computer systems have the same functionality as McGuckin, but are operated like K-Mart"

claim: to make an "economy of educational objects" a success, more is required than creating objects and depositing them in a globally accessible information repository

empirical fact: reuse is most successful within domains

not just objects, but:

- case libraries (different granularity)

- critiquing (accumulated "wisdom" of a community of practice

- specification component - partial characterization of a situation model

- simulation - to understand the behavior

- argumentation - to explore the rationale behind the artifact

SER model is a process model to seed, evolve and reseed an economy of educational knowledge