Human-Computer Interface in SIPE-2
In practical applications, natural pictorial representations are
necessary for a human user to understand the domain knowledge, the
plan, the planning process, and the execution of the plan. SIPE-2
provides a powerful graphical user interface (built on
Grasper-CL). Graphical tools can be
used for the following purposes:
- inputting
domain knowledge and creating operators
- following and controlling the planning process
- viewing complex information (including plans, operators, and
world descriptions) as graphs on the screen
SIPE-2 has five command menus. The PROFILE menu has commands for
setting defaults that allow the user to customize the behavior of the
system. The DOMAIN menu has commands that apply to the problem domain
as a whole, e.g., inputing and inspecting a domain. The PLAN menu has
commands that apply to a specific plan, including executing a plan and
solving a problem to produce a plan. The DRAWINGS menu has commands
that draw various SIPE-2 structures. Objects that can be drawn
include plans, operators, the sort hierarchy, the initial world model,
and problems. Finally, the NODE menu has commands that apply to
specific nodes in the currently drawn plan.
Graphical tools are available for knowledge acquistion. SRI's Act-Editor supports graphical displaying,
editing, and inputing of Acts.
SIPE-2 operators, plans, and problems can all be represented as Acts.
The Act-Editor provides a graphical knowledge-editor for both SIPE-2
and SRI's Procedural Reasoning System, since Acts can be translated
into either system. SIPE-2's sort hierarchy can be created, viewed
and edited using SRI's generic knowledge base editor, the
GKB-Editor.
SIPE-2 allows the user to control, when desired, many aspects of the
planning process. The user can decide when to apply certain planning
algorithms (known as plan critics), can choose which operator
to apply after the system has determined which ones are applicable,
and can choose which object to use for a particular action. At any of
these choice points, the complete power of the interface is available for
inspecting data structures (e.g., an operator can be drawn before
choosing it). The option of planning automatically for either one
abstraction level or for the rest of the plan is available. All
choices are kept so that different alternative plans can be developed
simultaneously.
The ability to understand what SIPE-2 is doing is
enhanced by the ability to highlight a node on the screen whenever the
system is making a decision about that node, e.g., planning for the
node, choosing an operator for the node, or choosing instantiations
for the variables at that node. Actions involved
in resource conflicts can be highlighted when interactive solution of
resource conflicts has been requested. If an ordering of two actions
is chosen, SIPE-2 will incrementally highlight and draw ordering links
as they are added. In particular, it flashes the first action, then
draws the ordering link, and then flashes the second action. This
gives an excellent visual depiction of how the plan is flowing.
During automatic planning, SIPE-2 provides a movie-mode in which
the system constructs pictorial representations of the plan as it is
being constructed.
SIPE-2 automatically lays out the actions of a new plan and gives the
user several options concerning which actions to display and what information
to display for each action. Many types of information can
be depicted graphically. For example, one can highlight all the
successors/predecessors of an action, all the actions unordered with
respect to an action, all actions that use a certain resource, or all
the actions that accomplish a certain condition.
As another example, the sort hierarchy can be displayed graphically as a
tree to help ensure its correctness. Clicking on an object in the hierarchy
will pop up a window displaying its attributes.
The following screen dump from SIPE-2 shows a plan depicted
graphically and the commands available in the DRAWING menu.
This image shows an oil-spill--response plan at a high
level of abstraction. The green hexagons are goals still to be solved
and the blue capsules are actions.
View full size in color, or
View full size in greyscale.
After expansion to the lowest level, this plan may contain hundreds of
actions. Large plan drawings do not fit on the screen in their
entirety, and are difficult to visualize. The interface provides
several techniques for viewing them.
- The graph window is scrollable,
so the user can pan over the whole plan.
- There is a birds-eye-view window that provides a low-resolution view of the
entire graph. This window can control the scrolling of the
full-resolution window, and the user can query graph relationships in
the birds-eye window.
- SIPE-2 gives the user several options concerning which actions to
display and what information to display for each action (invoked by the
NEW VIEW command). The displayed nodes
are mouse-sensitive and clicking them will cause them to be printed in
their entirety in a pop-up window.
- The commands in the NODE menu are particularly helpful when analyzing
large plans. These commands are
used to find and modify nodes, to find resources and predicates at
nodes, and to view, by highlighting nodes, various properties of a
plan. The modification options are useful for customizing the
appearance of the drawing on the screen ---- the user can move nodes
around with the mouse to make the drawing look exactly as desired. An
example of using highlighting of nodes effectively is the
Resource command which can be used to highlight all the nodes that
mention Fennario Port, effectively showing the schedule for that port.
A picture of a birds-eye view of a joint military
operations plan is also available, together with an image showing
more detail of some of the nodes.
SIPE-2, GKB-Editor, Act-Edtior and Grasper-CL are trademarks of SRI International.
Back to
SIPE-2 Home Page
David E. Wilkins
Last modified: Wed Feb 5 18:11:49 1997
