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Chapter 2
Prepositions
Prepositions are the words that link nouns, pronouns and phrases in sentences
and describe their relationships. These relationships include time (when),
possession (who/what), proximity (where), quantity (how many), cause (why)
and manner (how). Examples of typical prepositions include: with, in, on, at, by,
to, from and for. BEAM✲ uses prepositions to:
Link details to the main clause of an event.
Construct event stories using natural language sentences made from
main clause-preposition-detail combinations.
Clarify the relationship between an event and its details.
Discover event detail rules such as the time granularity of when details
(on, at) and the direction implied by where details (from, to).
Add the when detail
and preposition
to the table
After you have confirmed the prepositional phrase you add it to the event table, as
shown in Figure 2-4, with the on preposition above the new detail ORDER DATE.
Now that you have the subject, object, and initial when details you can begin to fill
out the table with event stories.
Figure 2-4
Adding the first
when detail
The preposition for a when detail is highly significant. “on order date,” “at call
time,” and “every sales quarter” each contain an important clue to the level of
time detail available (or necessary) for their respective events.
Collecting Event Stories
You ask the stakeholders to provide examples for every event detail you discover,
for the following reasons:
Asking for examples and getting useful answers is a clear indication that you
are being agile, that you are modeling with the right people: stakeholders who
know their own data.