Complexity, Metcalfe’s Law and Simplicity

Complexity can be defined as the number of components of a system, the number of relations between those components and the level of asymmetry in the structure of relations.

see also: What is complexity? by F. Heylighen

Robert Metcalfe, inventor of the Ethernet, is also the author of Metcalfe’s Law which states that the value of a telecommunications network is proportional to the square of the number of users of the system.

In the July 2006 IEEE Spectrum, Bob Briscoe, Odlyzko and Tilly argue that Metcalfe’s Law is Wrong because it overestimates the value of each connection. Reed’s law, on the contrary, suggests that Metcalfe’s law underestimates the value of adding connections since each member of the network is connected to individuals as well as subsets of the whole.

Metalfe’s law is general enough to be applicable to many systems. It has been used recently, for example, to argue for the “exponential” benefits of RDF and the semantic web


“the value of your information grows exponentially with your ability to combine it with new information.”

source: RDF and Metcalf’s law

In considering simplicity (the opposite of complexity?) in the context of interface design, I thought that this recent article by Luke Wroblewski made a pragmatic distinction between perception and reality


Many of us carry a few preconceived notions about simplicity. We assume things that are easy to use don’t have a lot of options and, as a result, shouldn’t appear cluttered when we first encounter them. In the world of product design, this means plenty of whitespace, clear calls to action, and an overall reduction of content—in the form of visual elements such as type, images, lines, colors, shapes, and so on. When a product has these attributes, we are more likely to assume it is easy to use. It’s quite possible that it might not be, but the perception of simplicity is there.

Conversely, a perception of complexity can turn customers, clients, or business stakeholders off before they ever actually use a product. In a worst-case scenario, an evaluation based on an opinion that “this looks cluttered; therefore, it must be difficult to use” can prevent customers from ever even trying a product out. But as Don Norman recently suggested, an initial impression of complexity might actually be an artifact of a product’s simplicity. In “The Truth About Google’s So-called ‘Simplicity’[…]

source: Complexity of Simplicity in UX matters

[Edited from Photomedia Forum posts by T.Neugebauer Jun – Dec, 2006]

icon design

Jonathan Follett’s recent article in UXMatters, Seeing the World in Symbols: Icons and the Evolving Language of Digital Wayfinding covers the history of icon design with links to important resources such as the AIGA universal graphic system and the icon archive at GUIdebook: Graphic User Interface gallery.


In Steve Caplin’s book Icon Design, Susan Kare, the artist who created the icons for the original Mac desktop and applications said:“In general, I believe that icons should work a bit like traffic signs; they should convey information without distracting the user, without competing with the data in an application. Ideally, they should suggest something about the functionality. If it is not completely evident, then the function should be easy to remember if the user is told only once.”


Today, two decades after their advent, icons unnecessarily clutter the desktops of new computers and the toolbars of applications. Increasingly, rather than performing a user-centered wayfinding function, they instead serve a corporate-centered branding function, with application icons becoming tiny billboards for Microsoft®, Adobe®, and their fellow competitors. We’ve turned our virtual spaces into the visual equivalent of the Vegas strip, but without the fun. If the primary purpose of an icon is to appropriately represent an action and help a person accomplish a task quickly, as this visual clutter increases, icons are increasingly failing at that task.

source: Seeing the World in Symbols: Icons and the Evolving Language of Digital Wayfinding. UXMatters, December 18, 2006


In addition to this, there are the following ISO standards for icons

ISO/IEC 11581:2000 Information technology — User system interfaces and symbols — Icon symbols and functions —

  • Part 1: Icons — General
  • Part 2: Object icons
  • Part 3: Pointer icons
  • Part 4: Control icons
  • Part 5: Tool icons
  • Part 6: Action icons

ISO/IEC 18035:2003 Information technology — Icon symbols and functions for controlling multimedia software applications
ISO/IEC 18036:2003 Information technology — Icon symbols and functions for World Wide Web browser toolbars
ISO/IEC TR 19764:2005 Information technology — Guidelines, methodology and reference criteria for cultural and linguistic adaptability in information technology products
ISO/IEC 24738:2006 Information technology — Icon symbols and functions for multimedia link attributes 

[Edited from Photomedia Forum post by T.Neugebauer from Dec 2006]

Information Design and Architecture

‘Information Design’ also known as “Information Architecture” (IA) and many other names, but we already knew from Gottlob Frege that a symbol can denote many senses…

The first book on Information Design that I read was this book, published in 2000:
Information Design

edited by Robert Jacobson.

I saw it at the MIT bookstore, and couldn’t resist…

One of the first online journals about usability is Boxes and Arrows, and I had the opportunity to attend a presentation and meet its founder Christina Wodtke…I think she was one of the founders of Information Architecture Institute… the presentation consisted largely of a film featuring interviews with various ‘information architects’…
the opportunity was partly the result of the recent IA Summit which just happened to take place in Montreal… one of the interesting applications
discussed at the summit was Flickr Photo Sharing…

Christina published a book on IA in 2002
Information Architecture: Blueprints for the Web 

Information design and information architecture is interesting to me, although it is a little bit like ‘informatics’, the meaning of this seems to be continually redefined with subtle nuances. the following list of disciplines are closely related:

I suppose the inter-disciplinary nature of information makes it difficult to label…

I just run across this article, and thought it was an interesting parallel between architecture and information architecture… i always thought that these have a lot in common…

We Are All Connected: The Path from Architecture to Information Architecture, by Fu-Tien Chiou

For architectures of large scale websites there is

Information Architecture for the World Wide Web: Designing Large-Scale Web Sites
wirtten by Louis Rosenfeld, Peter Morville. This 2nd edition was published in 2002.

Peter Morville published a new book on IA in 2005:
Ambient Findability

You can read an interview with Peter Morville in Boxes and Arrows by Liz Danzico

Designing Interfaces: Patterns for Effective Interaction Design

by Jenifer Tidwell, the book site ( offers a good summary of the contents. Jenifer Tidwell first presented a UI pattern language.

[Edited from Photomedia Forum post by T.Neugebauer from April 18, 2005 – November 18, 2006]

User-Centered Design

I have been reading about user-centered design for years, and find that the amount of web sites and sources about the subject is overwhelming. There are some key developments in the field that can get buried under all that information, such as the existence of relevant ISO standards:

ISO 13407 – Human-centered design processes for interactive systems (1999)

ISO 9241 (part 11) – Ergonomic requirements for office work with visual display terminals (VDTs) : Guidance on usability (1998)

The Human Factors Research Group (HFRG) at University College Cork (Ireland) has a good introduction to ISO 13407Jurek Kirakowski, director of HFRG also wrote Using ISO 13407 as a guide to personal knowledge and competence.




ISO 9241 (part 11) defines usability as


The effectiveness, efficiency, and satisfaction with which specified users achieve specified goals in particular environments.Effectiveness
The accuracy and completeness with which specified users can achieve specified goals in particular environments.Efficiency
The resources expended in relation to the accuracy and completeness of goals achieved.Satisfaction
The comfort and acceptability of the work system to its users and other people affected by its use. 


see also: – ISO 13407 – International standards for HCI and usability


some more interesting articles on usability:

Web-Based User Interface Evaluation with Questionnaires by Gary Perlman

Usability measurement in context (PDF) by
Nigel Bevan and Miles Macleod (Behaviour and Information Technology, 13, 132-145 (1994), National Physical Laboratory, Teddington, Middlesex, UK) In this study, the profile of perceived usability was subdivided into 5 subscales: Affect, Efficiency, Helpfulness, Control, and Learnability.


From a user’s perspective, the time he or she spends carrying out the task, or the effort
required to complete the task are the resources he or she consumes. These two types of
resources produce two different definitions of efficiency:Temporal Efficiency = Task Time = Effectiveness
Human Efficiency = Effort (e.g.: cognitive workload) = EffectivenessFrom the point of view of the organisation employing the user, the resource consumed is
the cost to the organisation of the user carrying out the task, for instance:¥ The labour costs of the user’s time
¥ The cost of the resources and the equipment used
¥ The cost of any training required by the user

In this case, efficiency can be stated as:
Economic Efficiency = Effectiveness


Measures of satisfaction describe the perceived usability of the overall system by its
users and the acceptability to the system to the people who use it and to other people
affected by its use. Measures of satisfaction may relate to specific aspects of the system
or may be measures of satisfaction with the overall system.


see also: – official U.S. Government Web site managed by the U.S. Department of Health & Human Services

Current practice in measuring usability: Challenges to usability studies and research by Kasper Hornbæk
International Journal of Human-Computer Studies
Volume 64, Issue 2, February 2006, Pages 79-102
open access version:

[Edited from Photomedia Forum post by T.Neugebauer from Sep 22, 2006 ]

InPhO – dynamic philosophy ontology

The Indiana Philosophy Ontology (InPhO) Project creates a dynamic formal ontology for the discipline of philosophy. The site allows you to browse the taxonomy and search Stanford Encyclopedia of Philosophy, Noesis (this was a search engine for open access, academic philosophy on the Internet) and Google Scholar. The project is described in the 2007 Joint Conference on Digital Libraries (JCDL) paper (ACM) and FirstMonday article.

[Edited from Photomedia Forum post by T.Neugebauer from October 29, 2007]