AsbruView
Introduction
Asbru is a very complex language, which cannot be understood by physicians, who have no or hardly any training in formal methods. AsbruView is a tool to make Asbru accessible to physicians, and to give any user an overview over a plan hierarchy.
AsbruView is based on visual metaphors to make the underlying concepts
easier to grasp. This was done because not only is the notation foreign
to physicians, but also the underlying concepts.
Two Views
AsbruView consists of two views: Tological View (TopoView)
and Temporal View (TempView). TopView only shows the principal layout,
and which parts of a plan are planned in sequence, in parallel, etc.
Topological View
The basic metaphor in this view is the running track (see image below).
Every plan is displayed as one such track, with metaphors to
symbolize different parts. The time dimension (from left to right)
is only a symbolic one, plans' sizes do not reflect their planned
duration. The traffic signs symbolize the preconditions: the "no entrance
with exceptions" stands for the filter precondition (which must be
true for the plan to be applicable at all); the barrier symbolizes
the setup precondition (which must also be true - but which can be
achieved by other plans if it is not - for the plan to be applicable).
The lights of the traffic light each stand for one futher condition.
red: the abort condition (which specifies when the plan has to be
stopped and regarded as failed); yellow: the suspend condition (which
defines when a plan has to be interrupted to treat an emergency, for
example); gree: the reactivate condition (which specifies when a
suspended plan can be continued).
The finishing flag, finally, symbolizes the complete condition,
which specifies when the plan has reached its goal and can be
considered successful.
Plans can have subplans, which are then stacked on top of the containing
plan (the so-called superplan).
Temporal View
In addition to the topological information, physicians need to be able to see the details of the temporal extensions of plans. For this purpose, the temporal view is used.
It consists of a display that represents each plan with a so-called glyph, i.e., a graphical object whose features change with the values they depict (see image on the right). It shows the four time points that mark the earliest start (ESS, earliest starting shift), latest start (LSS), earliest end (EFS, earliest finishing shift), and latest finishing shift (LFS). Lying on these points (similar to parts of a bridge on their supports), are bars that represent the minimum and maximum duration of the plan (MinDu and MaxDu) -- which are not 100% dependent on the start and end points, but are constrained by them (i.e., the MaxDu cannot be longer than the time between ESS and LFS, but can be shorter, so an action can take place during five hours, for example, but may not take longer than 15 minutes).
The plan hierarchy is also shown in this view in a way similar
to tree views like those used in file managers. Tree branches
can be folded, so that parts of the plan that are
not currently of interest are be hidden, and there is more space for
the interesting parts. Symbols left of the list of plans show
the plan type, e.g., sequential plans have a bullet next to every
sub-plan, parallel plans have two parallel lines, and any-order
plans have arrows pointing up and down (see figure below). The plans
with a questionmark-texture are optional, i.e., they do not have to
be finished for the containing plan to succeed, but can be dependending
on their conditions.
Conclusions
The metaphors and graphical representation of AsbruView have proven to be useful in communicating Asbru's concepts to physicians. Users get a better overview of the therapy steps than from tables, while at the same time being able to see the precise temporal constraints of plans (which they don't with flow-charts).
Using two different views for different information has also proven
to be quite useful because it helps to avoid cluttering the display
with too much information.
Selected Papers
These papers contain some more detailed information regarding AsbruView.
Robert Kosara and Silvia Miksch.
Metaphors of Movement: A Visualization and User Interface for Time-Oriented,
Skeletal Plans. In: Artificial Intelligence in Medicine,
Special Issue on Information Visualization in Medicine,
pp. 111-131, Volume 22, Number 2, 2001.
Robert Kosara and Silvia Miksch.
Visualization Techniques for Time-Oriented, Skeletal Plans
in Medical Therapy Planning. In:
Horn, W.; Shahar, Y.; Lindberg, G.; Andreassen, S.; Wyatt, J. (eds.),
Proceedings of the Joint European Conference on Artificial
Intelligence in Medicine and Medical Decision Making (AIMDM'99),
Springer, Berlin, pp. 291-300, 1999.
If you have any further questions, please contact
Robert Kosara
or Silvia Miksch.
