Processes of DesignFirst lecture:

Interactive System Design 3 October 2003

William Newman

Processes of Design: Overview

Method:• Explore principles• Study and discuss designs• Learn and apply methods.

Goal: gain an understanding all of the key steps in the process of designing an interactive system.

My background• PhD (Imperial College) in Computer Science,

1968• Six years at Xerox Palo Alto Research

Center, 1973-79• 15 years at Xerox Research Centre Europe

(Cambridge) 1987-2002• Mostly focused on designing experimental

interactive software systems• and on design methodology research• Now working as an independent consultant• Plus occasional teaching

Today’s Lectures

• Design• What is it• Examples to discuss• Are there underlying principles?

• Defining the design problem• Looking ahead…

What are Interactive Systems?

And what does it mean to design them?

What is design?

• Herb Simon:Everyone designs who devises courses of action aimed at changing existing situations into preferred ones.

• Designing material artefacts is like• Prescribing remedies to a sick patient• Devising a new sales plan for a company• Finding one’s way around a traffic jam…

What have we designed recently?

Even the Greats get it wrong!

• Rashtrapati Bhavan -- Edwin Lutyens’ Viceroy’s Palace

Alto: forerunner of today’s PC (1974)

• 1 Mhz processor

• 64Kbytes RAM

• 2 Mbyte disk yet…

• 5 Mbit Ethernet

• 808-line display

• 60 ppm laser printer

• WYSIWYG text editor, graphics editors, windowed desktop…

• See www.digibarn.com

The Bravo Word Processor

• Alto-based• Multi-font, almost WYSIWYG• Piece Tables• No menus or targets!

• Type i to insert, d to delete, e to select all, etc.

• The ‘edit’ problem• Exposed the Modes problem• Direct forerunner of Word

The “Big Bushy Tree” of PC software ancestry

Paths of design knowledge transfer

See http://www.digibarn.com/stories/desktop-history/index.html

Forget-Me-Not (Xerox Research

Cambridge, 1993)

'Factory' button

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What’s involved in design?

• Recalling Herb Simon:Everyone designs who devises courses of action aimed at changing existing situations into preferred ones.

• Involving…• Satisficing• Finding alternative solutions• Hierarchic subdivision• Simulation

Modelling what designers do

• Creative thought involves trial-and-error and selection

• See D. T. Campbell on Blind Variation and Selective Retention (1960)

known solutions

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What this means for designers of interactive systems

As designers, we need to know:• How to define and subdivide problems• Existing solutions and how [well] they work• Heuristics for varying existing solutions to

solve new problems• How to evaluate solutions empirically• How to predict outcomes analytically

As researchers, we need to make advances in all of these.