W3C Model-based User Interfaces Workshop, day 2

14 May 2010


See also: IRC log


Dave Raggett


MBUI and MDA Frameworks, Giorgio Brajnik, Università di Udine

<Steven> [Is the UML appropriate for Interaction Design?]

<Steven> Giorgio: Usability can be made better by providing tools that allow early evaluation

<Steven> ... you have to go into the details

<Steven> ... at the abstract level there are problems that cannot be caught

<Steven> Scribe: Steven

Giorgio: There are several approaches to model-based development
... most miss one important aspect
... they focus on the main model
... whis is not the right way to go when you want to focus on usability first
... state machines can help you here
... it is important to focus on details that affect usability
... at abstract and concrete levels
... one possible platform is wireframes, for debugging and user testing
... you can focus on accessibility
... such as testing without mouse access
... forcing you to show that you can navigate from the keyboard
... you could easily identify anti-patterns
... generate test scripts automatically
... analyse the interaction graph, prove reachability, and distance betwen states

[case study]

[Slide with state machine]

[Domain model]

[Wireframe prototype]

[Interaction graph]

Giorgio: The graph is complex, reflecting the complexity of the interface

Jose: I disagree that
... I disagree that this is helpful

Giorgio: This allows you to test assumptions

Jose: In the real world no

Giorgio: It allows you to test for consistency

[Usability problems]

Giorgio: There is for instance an unnecessary action for the user to return from the error message to the login screen
... potential usability problems like this can be extract4ed from the state graph
... State machines offer no expressivity limits
... don't ask you to express things you don't want to

Fabio: dynamic construction of interaction elements may be an expressivity limitation

Giogio: You could activate tasks

Fabio: You don''t know how many times it might be activated

MBUI in relationship to ISO/IEC 24752 Universal Remote Console, Jochen Frey, DFKI

Jochen: The URC has been an ISO standard since 2008
... there is a pilot store of 'apps' already running
... openurc.org is the consortium for the urc

Fabio: How do you connect the task model

Jochen: Done manually
... from task model to socket elements

Fabio: In what language?

Jochen: In the abstract description
... there is a task engine that plugs in
... the clients can be in any language, phones, PCs, java apps, c++
... the protocol is the important bit

aaa: How does the user integrate descriptions from resource server, to make updates on the UI

Jochen: This is still open

aaa: I have seen some RDF descriptions from the server

Jochen: The resource description uses RDF, but I am not an expert in this
... we are thinking about integrating semantics

MOSKitt UIM, Javier Muñoz

Javier: MOSKitt is a set of modelling tools
... there is no standard UML, and we need that really
... so we have just chosen one

bbb: The model-based approach is for richer applications of modern applications
... richer interfaces
... not for simple login screens
... practitioners don't see why you need a model-based approach for a login screen
... look at facebook and similar

Javier: We need to know how to model things, but for the new things there is no consensus yet
... we should have at least one standard language for the basic things

bbb: We should take in the new requirements when thinking about standardisation

Applicability discussion

dsr: We have a number of areas of discussion (see the agenda)
... What criteria determine whether a model-based UI design framework is appropriate to a given application? What are the main scenarios and domains where MBUI is valuable? Provide counter examples where it isn't appropriate.

Jose: The problem is to identify when the model based approach can be applied

Javier: I think that modelling can be used in practice

dsr: Are there counter examples?

Fabio: MB approach is good for multiple devices
... Not needed if you are only using a desktop system, except perhaps in safety critical systems

Daniel: Is this the right question to ask?
... all methods are model-based in some sense
... even when just programming
... sometimes using low-level machinery
... but the programmer must have some kind of model

dsr: So the model is implicit
... no reasoning about it
... is possible

Daniel: So what level should we go to

Pablo: The question is which level is appropriate

Daniel: We have to be more specific that just saying "model-based"

Pablo: When environments change, you need a model

Giorgio: It allows you to hide detail, and expose detail

dsr: For Dynamic adaptation, having a runtime model is important
... Accessibility is an example of this
... but going back to my question, are there examples that are not appropriate?

Jose: [Scribe missed]

<fpatern> models useful for accessibility, changing contexts, multi-device interfaces

Jose: something about the difference between concrete and abstract specification

ccc: How is the finalization of the interface reflected in the model

Jose: Good question

ccc: We need to address how you create a fabulous-looking website

ddd: It is hard to reverse engineer when there is no task
... no related task in the task model

ccc: Some approaches decouple both layers

Daniel: Most do

ccc: The final appearance is really important

Daniel: Most approaches allow for that, I am sure
... since you can generate arbitrary style markup
... I understand that many designers don't know how to use it
... but look at css Zen Garden
... it is possible

ccc: That is a question of best practices

Daniel: I mean that most approaches can decouple task process from style
... from look and feel
... some good designers are good at look and feel and interaction design
... but you can use different people
... Artistic designs are examples of where you don't need task designs, where there is no task per se

ddd: A real example is expression planet (?)

Giorhio: Another question: how usable are the tools?

Steven: You mean they haven't applied their own tools to their own tools?
...: -)

[Coffee break, 20 mins]

http://homepages.cwi.nl/~steven/vandf/2002.5-pixelpoint.html "Sooner or later it will get home to web designers not to design in pixels anymore, because each page will fit on a postage stamp if they do. "

"But at what point will they realise they shouldn't be designing their sites with fixed sizes at all, pixels or points, but using percentages, and letting the user decide on the base size, so that users can increase the base size to make the fonts larger and therefore more readable? Probably when their own sight starts to fade, around retirement age I suppose. "

<MichaelN> :-)

<kaz> scribenick: kaz


* modeling is needed but difficult

* which is easier, programming itself or modeling?

* usability testing?

- how to structure usability testing?

- different level of analysis could be useful to usability testing as well

wrapping up discussion - Fabio Paternò

(Fabio will take note online)

Summary of Action Items

[End of minutes]

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$Date: 2010/05/14 13:55:26 $

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Agenda: http://www.w3.org/2010/02/mbui/program.html
Got date from IRC log name: 14 May 2010
Guessing minutes URL: http://www.w3.org/2010/05/14-mbui-minutes.html
People with action items: 

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