Drawing TimeML Relations Marc Verhagen, Brandeis University

Outline Visualization of TimeML graphs Visualization history and future Procedure to display TimeML relations Consistency and drawability What about disjunctions? Temporal information in text widgets

Drawing TimeML Relations Visualization history and future Procedure to display TimeML relations Consistency and drawability What about disjunctions? Temporal information in text widgets

Alembic (1)

Alembic (2)

Tango

Other Efforts Using GraphViz (Luc Belanger) Event Diagram 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

Drawing TimeML Relations Visualization history and future Procedure to display TimeML relations Consistency and drawability What about disjunctions? Temporal information in text widgets

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)

Reducing the Graph (2)

Reducing the Graph (3) 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

Merging Branches (2) Simply draw arrow if merging in a re-entrancy after a before relation

Merging Branches (3) In some cases, arrows will go to the left, which is not allowed Simply move part of the drawing to the right

Merging Branches (4) Event included by two events, relates to the special display rule

Drawing TimeML Relations Visualization history and future Procedure to display TimeML relations Consistency and drawability What about disjunctions? Temporal information in text widgets

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?

Consistency vs Drawability (2) Closure throws an inconsistency Graph cannot be drawn Inconsistent graph, but it can be drawn

Drawing TimeML Relations Visualization history and future Procedure to display TimeML relations Consistency and drawability What about disjunctions? Temporal information in text widgets

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

Consistency vs Drawability (3) 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

Drawing TimeML Relations Visualization history and future Procedure to display TimeML relations Consistency and drawability What about disjunctions? Temporal information in text widgets

Displaying TLinks in Text (1)

Displaying TLinks in Text (2) 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 future Assign parts of the spectrum to these bins

Displaying TLinks in Text (3) Four kinds of events with simple scheme past present future unknown Scales up nicely when more precise information is available

Drawing TimeML Relations Visualization history and future Procedure to display TimeML relations Consistency and drawability What about disjunctions? Temporal information in text widgets

Future Work Yes