FIELD P 

 Columns 50 and 51 



If data from a single test are indefinitely reported as a range of time (e. g. , four days to two 

 weeks), an average value (in this case, 9 days) will be coded. This occurs occasionally when the 

 author describes a technique used in testing a series of compounds, and when he doesn't report the 

 exact duration of administration for each test run. However, do not code an average for such a range 

 unless the effectiveness, as coded in Field Y, is uniform over the total range. 



2. Coding of the actual exposure time in Field P, regardless of the maximum exposure time 

 characteristic of a special technique 



Care must be taken in coding Field P when an action is observed before the end of a standard 

 exposure period. For example, consider the technique for a standard screening test for toxicity. In 

 this test, each test compound is administered daily for a maximum of seven days. If the test compound 

 did not cause death at the dosage given, Field P should be coded with "seven days", but if death 

 resulted on the fourth day, Field P should be coded with "four days". Consider, as a second example, 

 a technique in which compounds dissolved in water are tested for their herbicidal effect on water plants 

 by growing the plants for three days in the test solution and then transferring them to tap water for an 

 additional four days of observation before an evaluation of their herbicidal effect is made. In coding 

 the herbicidal effect, "three days" (exposure time) would be coded in Field P and "seven days" in 

 Field V (time of evaluation). If, in addition, it is desirable to code production of chlorosis two days 

 after removal to tap water, the coding in Fields P and V would be 3 and 5 days, respectively. However, 

 if the chlorosis were produced two days after initiation of the test (i. e. , prior to the appointed time for 

 transfer to tap water), "two days" would be coded in both Fields P and V. 



3. Relationship between Fields O and P; the complication arising from Fields O and P having 

 two uses 



The two uses of Field P occasionally conflict. A thorough discussion of this will be found in 

 the Specific Directions and Explanations section for Field O (Division 8) to which reference should be 

 made. In brief, the information on time between administration of secondary and test compounds, when 

 they are not administered simultaneously, is always given preference. In a test in which the test 

 compound and secondary compound are not given simultaneously, and the test compound is subsequently 

 administered over a measurable period of time (indicated by any of Symbols 1 through 9 in Field O), that 

 duration of administration of the test compound can only be included in the written portion of Field P. 



4. Symbols available for additional items of Field P 



Inasmuch as the IBM zone punches have not been given special meanings in either column of 

 Field P, letter symbols are available for use, except that in Column 51 the CBCC restricts time range 

 coding to numerical symbols (i. e. , Symbols 1 through 9), to correspond to evaluation ranges in Field Y. 

 The ten scales now in the Code are fairly exhaustive of time ranges expected in most chemical- biological 

 tests. (Letters B through Z are available for any new scales needed. ) 



5. File of coded biology data on IBM punched cards arranged according to symbols for duration 

 of treatment 



No file of coded biology data in which Field P has been used has been established and arranged 

 by Field P entries. Information coded in Fields M, N, O, and P is of such a nature that sorting for it 

 is almost invariably subsequent to retrieval of information by specific actions, test organisms, test 

 compounds, etc. (for which there are special IBM files). 



6. Double coding in Field P 



If the evaluations of two or more tests are so similar that they are coded by the identical symbol 

 in Field Y and if the only variation in the two or more tests is the duration of administration (Field P), 

 all the durations of administration may be coded in Field P in a single line (always by the same Field P 

 scale, however, indicated in Column 50) and all punched in the same IBM card. (See the last paragraph 

 of Division 1 for coding a variation or range during a single test. ) 



If the only variation in two or more such tests is the length of time between administration of 

 the test compound and the secondary compound (indicated by Symbol or # in Field O), all these periods 

 of time may be coded in Field P and all punched in the same line. 



- 101 



