Loading ...
Sorry, an error occurred while loading the content.

RE: [usage-centered] UCD vs. XP

Expand Messages
  • Mark Collins-Cope
    ... You might like to look at www.ratio.co.uk/RSI.html - another approach to use case analysis which has some features in common with what you describe above -
    Message 1 of 44 , Jan 26, 2001
      At 09:50 25/04/01 -0400, you wrote:
      > Mark Collins-Cope wrote:
      > > A question: is there any focus in usage-centered design in
      > > factoring out the
      > > underlying functionality independently of the user interface?

      Larry wrote:
      > Yes. Usage-centered design separates system actors (representing other
      > systems and software) from user roles and system use cases, which support
      > system actors, from task cases, which support user roles. In addition,
      > system use cases may arise as included cases within task case narratives.
      > Collectively, system use cases drive the design of internal functionality.

      You might like to look at www.ratio.co.uk/RSI.html - another approach to use
      case analysis which has some features in common with what you describe above -
      although as documented there it uses Cockburn's style of documentation for
      business process type use cases. I've also used it using your (Larry's)
      essential use case form for the business process descriptions. This seemed to
      work well - so the paper needs updating - which I'll get around to at some

      How do you document "task case narratives." Are they essential use cases or
      some other form?


      > --Larry Constantine
      > Director of Research & Development | Constantine & Lockwood, Ltd.
      > 58 Kathleen Circle | Rowley, MA 01969
      > t: +1 978 948 5012 | f: +1 978 948 5036 | www.foruse.com
      > Yahoo! Groups Sponsor
      > <http://rd.yahoo.com/M=162801.1342250.2934640.1280005/D=egroupmail/S=17000
      > 07181:N/A=599089/*http://www.knowledgestorm.com/jump_white.html?c=Yahoo&n=
      > eLert_ComputersInternet_Software_WhiteGridOptions&t=ad>
      > Click Here to Find Software Faster
      > Your use of Yahoo! Groups is subject to the
      > <http://docs.yahoo.com/info/terms/>Yahoo! Terms of Service.

      Mark Collins-Cope
      |Voice: +44 (0)20 8579 7900 Fax: +44 (0)20 8579 9200|
      |Mobile:+44 (0)777 163 6882 Email: markcc@... |
      |Post: 17-19 The Broadway, Ealing, London W5 2NH, UK |
      |RATIO: OO Training Tools Consultancy Recruitment |
      |Training: C++, Java, EJBs, CBD, UML, OOAD, XP, XML, |
      |See ObjectiveView technical journal: www.ratio.co.uk |
    • Nuno J. Nunes
      on 30/04/01 08:40, Hallvard Trtteberg at hal@idi.ntnu.no wrote: Hallvard, ... I m familiar with Paternò s interactors. That approach is very close to the
      Message 44 of 44 , Apr 30 4:29 AM
        on 30/04/01 08:40, Hallvard Trtteberg at hal@... wrote:


        > The abstraction is close to the "York/Piza" interactors, which in short
        > introduces a basic UI building block called "interactor" which mediates
        > information in two directions, user to system and system to user, through
        > four "gates". In my notation, the interactor is a rectangular box with
        > title, triangular gates and a resource interface. I've introduced functions
        > and merged these with gates, to provide domain specific computations.
        > Interactors are put together a bit like lego-bricks, by connecting the gates
        > and can be nested into a hierarchical graph, similar to a process network. I
        > formalise part of this using Statecharts, while the process algebra LOTOS
        > has been used by others. If anyone is particularly interested, I can send
        > him/her parts of my thesis, where this is discussed in relation to concrete
        > interface elements.

        I'm familiar with Paternò's interactors. That approach is very close to the
        model-based tradition, which was popular years ago but failed to gain
        widespread support mainly because model-based environments (including
        back-to-back automatic generation) never proved to be effective in practice.

        I'm not saying this approach is wrong or flawed, it surely is sound from a
        theoretical perspective. The main problem is that "pure" model-based
        approaches (in the sense that they attempt to fully automate the UID
        process) have not proved to be flexible enough for modern UIs. There are
        other successful examples of automatic generation techniques, mainly the web
        - where UIs described in markup are rendered in different platforms.
        However, those successful examples are very limited in terms of the extent
        to which they support the UID process.

        Times are changing though. Today we're moving away from the stable desktop
        paradigm and there is an increasing number of target platforms that differ
        substantially in terms of the devices we use to interact, and the related
        interaction styles and techniques.

        My point is that model-based techniques will inevitably come into play
        again. It will be very difficult to deploy software systems over a series of
        different platforms (just think of desktop, web, palm, cellular phone, and
        interactive TV) without effective model-based techniques. It's not a matter
        of whether we like them or not... We just can't cope with the increasing
        complexity without model-based approaches.

        > I want this to be a practical tool and have experimented with a runtime
        > system for this. I'm also working on a mapping to UML through stereotypes,
        > which I guess you're particularly interested in.

        Sounds interesting... Can you send more info on that UML adaptation? Is the
        runtime environment available?

        > I like to call the UID patters, i.e. both user interface and design. If we
        > omit "design" these may wrongly regarded as software patterns.

        I prefer a different distinction:
        Software patterns - all patterns that have to do with software
        Design patterns - patterns that have to do with OO design
        Analysis patterns - same for OO analysis
        UI patterns - patterns that have to do with UIs - interaction patterns,
        UID patterns, etc. are different classes of UI patterns.

        Nuno Jardim Nunes
        University of Madeira - Teaching Assistant
        Mathematics Dep. - Computer Science Unit
        phone: +351 291 705160 (direct) 705150 (secretary)
        fax: +351 291 705199
        URL: http://math.uma.pt/njn/
        Address: Campus Universitário da Penteada
        9000 - Funchal - Portugal
      Your message has been successfully submitted and would be delivered to recipients shortly.