This document discusses various methods used to measure biodiversity, including biological sampling techniques to estimate species density and abundance. Some key methods mentioned are line transects, quadrats, capture-recapture, traps, aerial photographs, and counts of artifacts. It also discusses indices to quantify biodiversity, such as Simpson's Index and Shannon-Wiener Index, and gives examples of their calculation and interpretation. Finally, it covers topics like endemism levels in Australia and measures of extinction risk.