“A ‘Physics’ of Notations”? Ideas of Daniel L. Moody Presented by J. David Andrews Ph.D. Candidate School of Computing

Main Reference The “Physics” of Notations: Toward a Scientific Basis for Constructing Visual Notations Software Engineering, IEEE Transactions On Software Engineering, VOL. 35, NO. 6, November/December 2009 March 12, 2013“A ‘Physics’ of Notations”?2

UML UML as a communication medium. Strongly visual at top level. Two Medium/Large scale projects that used UML (Rational). – One poorly. – One well. March 12, 2013“A ‘Physics’ of Notations”?3

Poor Use UML used as document production system. Communication to non-developers: – Used Rational Rose as documentation system – For MIL-STD paper documentation. Communication to developers. – Ill-conceived class hierarchy. – Forced OO on objects ill-suited for it. March 12, 2013“A ‘Physics’ of Notations”?4 I’m not even written in an OO Language! Hello up there! We the classes need to be redesigned.

Good Use Good communication to non-technical people. – Use cases. – Rapid prototypes. – Etc. Well conceived UML diagrams. Not infected with ‘UML fever’. Death by UML Fever, ALEX E. BELL, THE BOEING COMPANY’.UML fever March 12, 2013“A ‘Physics’ of Notations”?5

My Initial Reaction Quite negative. In the ‘good old days’ … – Fetzer: Program Verification: The Very Idea, Communications of the ACM, Volume 31 Issue 9, Sept. 1988, Pages Fetzer – What some readers thought he said: “software verification is worthless”. – What Fetzer said, “however much software verification one does, the hardware is still subject to failure.” March 12, 2013“A ‘Physics’ of Notations”?6

Physics? Let’s ask a physicist. March 12, 2013“A ‘Physics’ of Notations”?7 Pseudoscience. But good pseudoscience. And needed pseudoscience. Physics here is a metaphor. For a systematic theory of picture-based communication.

Semiotics/Ontology Huh? Signs Reality March 12, 2013“A ‘Physics’ of Notations”?8

What do signs give us? By themselves? Not much … Used intelligently? More, obviously … But how much more? March 12, 2013“A ‘Physics’ of Notations”?9

Towards Moody is saying: – We aren’t there yet. – But we want to be. – And here are some ideas to consider. Ideas often best formulated by … – People we tend to dismiss as pseudoscientists. So I’ll let Moody speak. In his own pictures. March 12, 2013“A ‘Physics’ of Notations”?10

Focus: March 12, 2013“A ‘Physics’ of Notations”?11

Visual Dialects March 12, 2013“A ‘Physics’ of Notations”?12

Ontological Analysis March 12, 2013“A ‘Physics’ of Notations”?13 Essential for good communication.

Communication March 12, 2013“A ‘Physics’ of Notations”?14

March 12, 2013“A ‘Physics’ of Notations”?15 Color left out of UML for political correctness. But why should ‘color’ be rendered by color? Or ‘texture’ by visual texture?

March 12, 2013“A ‘Physics’ of Notations”?16 Solution Space Principles Extensible solution

Perceptual Discrimination Visual Distance Shape (prime importance). Redundant Coding Perceptual Popout Textual Discrimination March 12, 2013“A ‘Physics’ of Notations”?17

March 12, 2013“A ‘Physics’ of Notations”?18 Semiotic Clarity

March 12, 2013“A ‘Physics’ of Notations”?19 Semantic Transparency

March 12, 2013“A ‘Physics’ of Notations”?20 Manageable Complexity

March 12, 2013“A ‘Physics’ of Notations”?21 Cognitive Integration For example:

March 12, 2013“A ‘Physics’ of Notations”?22 Visual Expressiveness

March 12, 2013“A ‘Physics’ of Notations”?23 Dual Coding Text and Graphics …

March 12, 2013“A ‘Physics’ of Notations”?24 Graphic Economy

March 12, 2013“A ‘Physics’ of Notations”?25 Cognitive Fit For different kinds of users With different skill levels. Etc. Images from Wikipedia

Thank you! March 12, 2013“A ‘Physics’ of Notations”?26