Which occurrenceStatus rule a dataset falls under

Measured from the data, never declared:

Usage

dwc_absence_rule(con, dataset_key)

Arguments

con

a DBI connection to the release

dataset_key

the dataset

Value

"zeros_recorded" or "positive_only".

Details

• "zeros_recorded" — the dataset has zero-valued obs_bio rows, so a sample that was examined and held none of a taxon is already in the release. Those rows become occurrenceStatus = "absent" and nothing is derived.

• "positive_only" — the dataset has no zero rows: a surveyed-empty sample simply has no row. occurrenceStatus is "present" for every row it does have, and an absence exists only if the protocol sorted every sample for the whole vocabulary — a claim about the protocol that the release cannot make. dwc_occurrence() therefore derives absences ONLY when asked (absences = "sample_root").