VENRICK: PERCENT SIMILARITY: THE PREDICTION OF BIAS 



more sharply. Thus, minimum values of j3 are asso- 

 ciated with values of//' < 0.25 and // ~ 1.0, while 

 maximum values occur at some intermediate value of 

 H , possibly influenced by the number of species. 



The shaded area in text Figure 4 approximately en- 

 compasses the maximum and minimum values of fi 

 observed empirically over a broad range of//'. Much 

 of the variability in the estimated /? apparent in 

 Figures 4 and 5 is due to errors in the empirical deter- 



mination of the true variance of/; with 100 samples in 

 each estimate, 95% confidence intervals are 0.47 s 2 — 

 1.35 s 2 . Although the value of /? cannot be determined 

 with sufficient accuracy to allow Equation (9) to be 

 used to establish confidence intervals about predict- 

 ed values of/, nevertheless the figure can be used to 

 provide conservative estimates of fi so that Equation 

 (9) may aid in decisionmaking. 



387 



