On the use of species-area curves to detect the effects of sample size

Archaeologists have long been concerned about sample size. To monitor the relationship between sample size and the magnitude of a variable of interest, archaeologists have constructed three distinct kinds of what in ecology are known as species area curves (SACs). Sampling to redundancy SACs involve adding successive samples cumulatively to determine if the information provided by new samples is unique or redundant with information provided by earlier (smaller) samples. Rarefaction SACs involve pooling multiple samples and then rarifying the pooled sample—making it smaller probabilistically—so that the originally large but rarified sample may be compared with originally small samples. Regression SACs determine if there is a significant statistical relationship between samples of different sizes and the magnitude of the variable of interest per sample. Each of the three SACs used by archaeologists has a distinct analytical purpose.