> Subcategory taxonomy provides a series of pick lists for Protocol authors. After selecting a Subcategory, authors then enter a title for their specific Metric or Indicator.

All sites in the study area are sampled.

Only sites within a part of the study area are sampled.

Selection of sites is based on the need to estimate parameters or coefficients of a model that will be used to make the population estimates.

Selection of sites in part of the study area is guided by the candidate model, and locations in other parts are selected by other methods.

Sites are chosen based on their relative ease of access.

Sites are chosen because they have been studied in the past (e.g., Index Reaches).

Spatially-balanced random sampling.

Sampling in which a population is divided into clusters (or 'natural' groupings) and a random sample of those clusters is chosen for sampling. Each member of the cluster is then sampled.

A type of cluster sampling in which a population is divided into clusters (or 'natural' groupings) and a random sample of those clusters is chosen. Instead of sampling each member of the clu [..]