amounts are accompanied by the frequency with which each range is found in 

 association with the same very high and very low population densities. 



The second part of the system is a one-page density calculation form (Figure 3). 

 Each response to the questionnaire is recorded on the form when a tract is being 

 evaluated. All calculations are then made, a process that takes about three minutes 

 with a hand calculator. The concepts and mathematical theory upon which the 

 PATREC system is based are reported in Williams et al.^ and are derived from 

 mathematical procedures used for a number of years for medical and business 

 decisionmaking. 



S- 





>'<K/^<> 



p«cles 



PATREC 



pornrriAi, densxty 





'D«y / Month / Y««r 



(acraa) 



(•q. ■!.) 



Saiulcy Probabllldaa: 



13 



Product J : (A).^o<ipy^^ ina«oo/eV 



[r^] 



ZsiL 



uJUL 



-P-L _ 



^-"».tty Standards (C) S<S/ %, I "*- (D) /V^/ >• 



'(high) ' (low) 

 ■Density Eitlaaca: .i'J.lf.So > ,/f^)t. / - 'jfjf . potaatlai danslty on chl» tract 



(p.U z C) (p.L X 0) 'or thaaa conditions 



" /^ 3 potancial population on this 



Tract slza Tract danalty tract for thasa conditions. 



' Population aatlaata: O.O 



Coaaanta or Spaclal Conditions: 



CCWRU 

 Oct 1979 



Figure 3. PATREC Potential Density Calculation Form — Sage Grouse. 



178 



