Number of Identified Specimens (NISP)

Not necessarily. NISP counts identifiable fragments, so a taxon can score high simply because its bones fragmented into many pieces, were better preserved, or were more recoverable, rather than because more individuals were present. To judge past abundance from NISP you must control for fragmentation (for example by inspecting the NISP-to-MNE ratio), hold the identification criterion constant, and ensure recovery was comparable. Interpreted as a relative, ordinal signal under these controls, NISP is informative; read as a literal abundance count, it can mislead.

Because the units counted are specimens, not elements or animals, and several specimens can derive from the same bone of the same animal. Two refitting fragments of one femur count as two toward NISP even though they represent one element of one individual. This means NISP observations are not independent draws, which inflates counts unpredictably and invalidates statistical tests that assume independence. Recording conjoinable fragments and, where feasible, reducing to the minimum number of elements mitigates the problem.

Screen (mesh) size controls which bones are recovered, and small bones and small taxa pass through coarse mesh and are lost. An assemblage sieved through fine mesh will have a very different NISP profile — typically far more fish and small mammals — than one recovered through coarse mesh or hand collection. Because of this, raw NISP values are only comparable across assemblages recovered with the same method and mesh, and reports must state recovery conditions before NISP-based comparisons are drawn.