ObservedEvent

This group looked first at several existing event models (see References below) and found they by and large focus on aspects of participation and spatial-temporal location. We noted that two other important aspects were missing or underspecified: Event as instance of change, and Events' identity as information objects reflecting intentionality and purpose.

The design pattern undertaken, Observed Event, models the case of an Event changing the State of a GeoThing. In doing so it is seen as complementing the good work done already which focuses on the participation relation.

A Note on Patterns: Event and Process are broad concepts which have proven notoriously difficult to define. Rather than distinct concepts, they can be viewed as perspectives on the very large class of discrete temporal objects. Two of the patterns undertaken at GeoVoCamp2012SB concerned events, and the "seams" the two groups found were, in one case 'relations for which Event is the domain' (changes-state versus has-participant), and in the second case, Event types (MotionEvent and associated Paths). This suggests that relations and types may be the best place to look for dividing large concepts into manageably-sized design patterns.

Observed Events and the Changes They Cause

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Axioms

• Earth Processes (at relevant scales) are continuous
• Processes produce observable, discrete Events (snapshots)
• Events are observations from data, not in the world
• A GeoThing has a collection of States and an Identity
• Event produces new State of GeoThing
• Events have spatial and temporal extents
• Or Event produces new GeoThing (change of Identity)
• Change of State is observed (or not) (and interpreted...)
• Events have location & time; they correspond to the state change and Spatial Extent of the GeoThing
• Temporal Extent has Start Time and End Time
• (rule or constraint?) Temporal Extent of GeoThing inherits Start Time from Event (and previous State inherits End Time

References

• (Shaw et al 2009): LODE; Agentive participation, non-agentive involvement or presence, temporal and spatial (inSpace, atPlace) location; illustrated-in
• (Ruotsalo & Hyvönen 2007): FinnOnto; place, time, participant (incl. agent and patient), goal and instrument
• (van Hage et al 2011): Simple Event Model (SEM); Core classes: Event, Actor, Place, Time; unlimited sem:Type vocabularies; constraints: Role, View (of authority), and Temporal portion.
• (Grossner 2010): Event Objects for Spatial History; Events (and sub-event parts) composed of activity, modeled as an aspect of participation (performedActivity in role); Historical-process ≈ theories of event relations (e.g. caused, requires)
• (Heise 1991): Event Structure Analysis (ESA); methodology and software, ETHNO, for representing logical relations between events within larger, complex event sequences…sequences of social events grounded in chronology and linked together to create historically and temporally based causal interpretations of history