FIELD U 

 Columns 65 and 66 



Field X Log-probit Grid 



Criterion 54 Reciprocal of the value coded in Column 66 (on abscissa) 



--vs. cumulative per cent organisms responding (on 

 ordinate) 



Criterion 57 Reciprocal of the value coded in Column 66 (on abscissa) 



--vs. cumulative per cent organisms responding (on 

 ordinate) 



Criterion 58 The value coded in Column 66 (on abscissa)--vs. 



cumulative per cent organisms responding (on 

 ordinate) 



Criterion 59 The value coded in Column 66 (on abscissa)- -vs. 



cumulative per cent organisms responding (on 

 ordinate) 



> 



Field Y 



Values, derived 

 from plotting on 

 the Grid. 



These criteria are discussed in detail in the Specific Directions and Explanations section for 

 Fields W, X, and Y, Division 20; the illustrations at the end of that division should be studied to 

 understand the plotting of the cumulative per cent of organisms on the ordinate of the Grid. 



9. Conflict between uses of Field U: persistence of activity of residue vs. any of the time 

 values used for evaluation coded in Fields X and Y 



In the event that the response to the test compound residue is evaluated by "killing time", 

 "time to specific response", or "duration of action" (each of which would require an entry in Field U) 

 and the persistence of the activity of the residue has been determined, a conflict arises in the use 

 of Field U. 



This conflict is resolved by the provision always to use Field U for coding the persistence of 

 the residue when it has been demonstrated. This is permitted for the following reason. Even though 

 Field U is occupied with a persistence-of-activity-of-residue value (as will be evidenced by Symbol * 

 in Column 66), Criterion 10, 11, 58, or 59 (but not 13 or 54) can be used- -by virtue of the fact that 

 the "time to specific action" or "killing time" is always identical to the "time of evaluation" which is 

 coded in Field V; thus, when Criterion 10, 11, 58, or 59 is used in Field X and Symbol * appears in 

 Column 66, the time value in Field V represents the "time to specific action" or the "killing time" as 

 well as "evaluation time". The coding in Field Y in this case would be derived by consulting the code 

 scales of Field U to determine the coding that would have been in Field U had it not been occupied by 

 persistence-of-activity-of-resldue data. Note, however, that coding in Field V is not identical to a 

 "duration of action" (Criteria 13 and 54) and if Field U is occupied with "persistence of activity of a 

 residue", there is no way to code a "duration of action". Therefore, when persistence of activity of 

 a residue is coded in Field U, Criterion 13 or 54 must not be used in Field X; this is little disadvantage, 

 since it is so improbable that in a typical test for persistence of residue, an evaluation of the indi- 

 vidual tests would be made on the basis of duration of action. If this latter conflict should arise, 

 construction of a second code line is recommended in which the duration of action would be coded in 

 Field U, Criterion 13 or 54 used in Field X, and, in the written abstract of Field U, attention would 

 be called to the preceding line in which is coded the persistence of residue. 



This CBCC choice of giving precedence to the persistence-of-activity-of-resldue information 

 was due to the coding initially of a large amount of insecticidal data, for which persistence-of-activity- 

 of-residue data are particularly important. It is suggested that for projects other than the CBCC, a 

 precedence might be given to other information for Field U or the procedure established of coding a 

 line for each time value for which Field U is used. 



10. Symbols available 



Although the ten scales now in Field U are fairly exhaustive of the time ranges expected in 

 most chemical- biological tests, letters J through Z are available in Column 65 for any new scales 

 needed. The CBCC restricts time range coding to numerical symbols (i. e. , Symbols 1 through 9) to 

 correspond to evaluation ranges in Field Y. 



166 



