The ASUR model
- Main contributor: E. Dubois
- Other contributors:
P. Gray, G. Gauffre, G. Masserey, B. Mansoux, L. Nigay
ASUR is a notational-based model for describing user-system interaction in mixed interactive systems. ASUR is intended to help in reasoning about how to combine physical and digital “worlds” to achieve user-significant results. It is used in addition to a traditional user-system task description in order to identify objects involved in the interaction and at the boundaries between the two worlds. Adopting a user’s interaction point of view, the model is helpful in expressing the results of the requirements analysis and addressing the global design phase of a mixed interactive system.
To do so, ASUR is based on the identification of the particiapting entities and relationships among them, that are called interaction channels
IllustrationA concrete illustration of the use of the ASUR model and its characteristics is shown in this example. It is based on the Google Earth project.
A more progressive presentation of this case study is given in the paper published in the Physicality 07 workshop.
Participating entities (ASUR component)
Modelling an interactive situation with ASUR requires identifying the components involved. They are the participating entities and can be of four different types:
- “A” component refers to adaptors, used to bridge the two worlds. Ain components convey data from the physical to the digital world, such as a camera. Aout components carry data from the digital to the physical world such as a video-projector for example.
- “S” component depicts the computer system, including computational and storage capabilities and data acquisition and delivery. Three different S component exist:
- An Sobject represents the object of the task, real focus of the task.
- An Sinfo component depicts a digital domain object
- An Stool component represents a digital elements used to achieve the task, supporting an articulatory task (such as a magic lens on which to act to modify the color of the underlying object).
- “U” component refers to the user of the system.
- “R” components denote physical entities involved in performing the task. Two different physical objects exist:
- An Robject designates the real focus of the task. It is the equivalent of the Sobject.
- An Rtool plays the role of intermediary entities required to perform the task.
Interaction channels (ASUR relationships)Different type of relationships have been identified:
- Data Exchange, is used to express the kind of data transmitted between each component. In the physical part, they represent channels of communications between entities, and in the digital part the way the system transmit and transform them.
- Representation links express coupling between a physical component and a digital component in terms of behavior and rendering.
- Real associations express physical proximity of two physical entities (close to, contained in, ...)
- Triggers represent an action of one component over another which triggers a Data Exchange between two other ASUR components.
A more detailed presentation of the components and relationships is given, explained and illustrated in the paper published at IWC'03 and complemented by chapter of the book on Design and Evaluation of Mobile UI..
The latest update is presented in chapter 4.1.3 of the book entitled "Model Driven Develoment of Advanced User Interfaces"
[Guillaume Gauffre , Emmanuel Dubois . Taking Advantage of Model-Driven Engineering Foundations for Mixed Interaction Design. Dans : Model Driven Develoment of Advanced User Interfaces . H Hussmann, G Meixner, D Zuehlke (Eds.), Springer-Verlag , 4.1.3, p. 219-240, Vol. 340, Studies in Computational Intelligence, 1, 2011.]
Global characteristics of the interaction channels
Channels are first characterized by the medium:
it is the means by which the information is transmitted.
It may be any physical characteristics used to communicate the information properties of a digital connection. For example a medium can be the light, vibrations, pressures, or more complex such as a physical configuration of a physical object. A medium can also be digital.
Channels are also characterized by the representation:
it is the coding scheme used to encode information onto the medium.
It might be a set of predefined values, a sentence, an image, the position of an artifact, etc.
Global characteristics of the participating entities
Participating entities can be differentiated according to their
method of modification: it refers to the method of affecting the medium.
It might be light modulation, tremor, a set of motions, etc.
Participating entities offer different sensing mechanisms:
the devices or processes used to capture the state or changes of the medium.
It may be a camera, microphone, or any sensor and human perceptual senses. In some cases, the sensing mechanism is not applicable: a channel denoting the user’s grasp of a physical artifact may have a sensing mechanism but is not of interest for a MIS designer. Similarly, when the medium of a channel is digital, its sensing mechanism may be of interest for software engineer in the later phases of MIS design.
Global characteristics of the overall interaction pathFinally, the interaction path is associated with an Intended User Model that describes what the user should know about the interaction. It includes the information intended to be communicated (IUM content) and any other required information (IUM context) such as the place where the actions must take place in order to be understood by the system.
A more detailed presentation of these global characteristics is given, explained and illustrated in the paper published at EIS'07.
Detailed characteristics of the interaction channelsSuch characteristics support the description of the language used to represent the information (language property): possible values are arbitrary, analog, etc. It is also the place to precise whether the form of the language in output is textual, graphical, etc. or, in input, gestural, physical or a language and from wich point of view the data is represented (ego centric, exo centric, ...)
Detailed characteristics of the participating entitiesThis is for example used to precise where and how an information will be provided by an adapter to a user (perception sense). Possible values are visual, tactile, audio, etc.
Detailed characteristics of the overall interaction path
So far, no characteristics have been identified at this level.
A more detailed presentation of these detailed characteristics is given, explained and illustrated in the paper published in the journal IWC'03.
PropertiesA set of ergonomic properties ahve been expressed as a boolean expression of ASUR characteristics. For example we have defined the "cognitive continuity" as a set of interaction channel characteristics: all the interaction channels linked to the user must have the same point of view and language.
A more detailed presentation of the definition and use of these ergonomic properties is given, explained and illustrated in the paper published in the journal IWC'03.