drawing timeml relations marc verhagen, brandeis university

Drawing TimeML Relations

Marc Verhagen, Brandeis University

Outline

Visualization of TimeML graphs

1. Visualization history and future

2. Procedure to display TimeML relations

3. Consistency and drawability

4. What about disjunctions?

5. Temporal information in text widgets

Alembic (1)

Alembic (2)

Other Efforts

• Using GraphViz (Luc Belanger)– Works nice for small samples, does not scale

up gracefully

• Event Diagram– Take one event and group all others around it

• Using Petri Nets (Natalia Kotsyba)– More boxes in representation than there are

events in the text

• Tango improvements (Nick Chubrich)– Color-coding, skirts

Current Tango

Future Tango

Side by Side

Display Rules

Simultaneity

Precedence

Inclusion

Begins/Ends

Display Rules - special case

One event is included by two other events that have no further relation to each other

Example Fragments (1)

Example Fragments (2)

Drawing Procedure

Input to Drawing Procedure

TimeML annotation that is maximal and consistent

Temporal Closure (1)

• Consistency and maximality are guaranteed by temporal closure

• SputLink: temporal closure based on Allen’s interval algebra, but using restrictions from point algebra

• Implications for annotation task(in short: closure makes it feasible)

• Added as a module to Tango

Temporal Closure (2)

Reducing the Graph (1)


• Create equivalence classes

• Convert to basic set of relations:– before, ibefore, includes, begun_by,

ended_by– eliminates cycles

• Use temporal closure rules for reductions– [X ibefore Y] & [Z ended_by X] & [Z ibefore Y]

==> delete [X ibefore Y]

The Reduced Graph

It’s a… directed acyclic graph

Create Pseudo AVM

Basic Mapping Rule

• Draw a bar for 0 in the top left corner • For every before attribute, remove the

attribute and draw an arrow from bar 0 to the drawing that is the value of before

• For every includes attribute, remove the attribute and move the value of the attribute to the box underneath 0, draw the box if there isn't one yet.

• If there are no more attributes in the box, remove the box (but keep the contents)

• Remove the label of the box if its ID is the same as the head of the drawing.

Basic Mapping Rule at Work

Merging Branches (1)

• There are three special cases for which we cannot use the basic mapping rule

Note that there are more cases when ibefore,begun_by and ended_by are included


• Simply draw arrow if merging in a re-entrancy after a before relation


• In some cases, arrows will go to the left, which is not allowed

• Simply move part of the drawing to the right


• Event included by two events, relates to the special display rule

Consistency vs Drawability (1)

• Can any consistent graph be drawn?– Yes, see the drawing procedure– Need a more formal proof

• Can an inconsistent graph be drawn?– No, first step is to run closure– Yes perhaps, what about drawings that are

constructed differently?


• Closure throws an inconsistency• Graph cannot be drawn

Inconsistent graph, but it can be drawn

Disjunctions (1)

• TimeML does not yet have disjunctions, but may need some soon

• Closure uses 29 relation types, 16 of them are disjunctions

• All those 16 disjunctions can be mapped to drawings

Disjunctions (2)

Disjunctions (3)

• Some disjunctions are still not available to us:“He got promoted on Wednesday or Friday”

• No neat way to localize or encapsulate disjunctions in TimeML graphs, but use multiple positions in TimeML drawings


• Adding the disjunctions– Expanding the drawing procedure– Not necessarily a good idea to draw all

disjunctions– Does drawability now imply consistency?– Previous example cannot be drawn

Displaying TLinks in Text (1)


• Temporal information by color-coding events• Problem: if two events have the same color,

then you assume they are at the same time• Use a bar with a spectrum that spans the

whole TimeML graph in a document

Distinguish three bins: past, present and futureAssign parts of the spectrum to these bins


• Four kinds of events with simple scheme

past present future

unknown

• Scales up nicely when more precise information is available

Future Work

Yes

drawing timeml relations marc verhagen, brandeis university

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