Fig 2. Annotation accuracy.

Accuracy as measured by Cohen’s kappa for the Hosts’ annotations with various level of alleviation, and for the Visitors’ (mean ± SD, n = 5) annotations. The left edge of the alleviation curve corresponds to automated annotations only, and the right edge corresponds to the Hosts’ annotations only. The first column shows accuracy calculated from the full label-set. Column two to five show accuracy for the task of discriminating functional groups: coral, macroalgae, crustose coralline algae (CCA), and turf algae, respectively, versus the rest. Columns six, seven and eight show accuracy for the three dominant coral genera. Genus-level identification for Heron Reef is not provided, as Archived annotations were not available to this resolution.