FIELD V 

 Column 67 



8. Double coding 



It is possible that more than one measure of activity or point of observation may fall within 

 the range of evaluation assigned to one symbol of Field Y, yet for each of these the time to evaluation 

 would be different. The following two examples will illustrate this. (1) Ten minutes after adminis- 

 tration of a test compound, the response was read as 42% increase over normal; 10 minutes later, it 

 was 44%; subsequent readings at 10 minute intervals were 46%, 42%, 10%, and 1%. In this case, 

 the coding of Field Y would be of the highest activity (46% increase over normal), yet the symbol of 

 Field Y which codes this (Symbol 4 of Criterion 62), by the broadness of its definition, actually 

 represents any of 42%, 44%, 46%, and 42%. The period over which the response remained within 

 the levels represented by the symbol of Field Y was from 10 minutes after administration through 40 

 minutes after administration (four "times to evaluation"). (2) A second example is that of several 

 separate tests of the same compound, differing only in "times to evaluation"; if the results of two or 

 more of these tests are so similar that they are all represented by the same symbol in Field Y, the 

 same situation exists as in Example 1 above; i. e. , the code symbol in Field Y represents evaluations 

 from several "times to evaluation". Because of the dependency of Field V on Field Y, Field V can be 

 coded with time periods no more precise than the coding in Field Y; therefore, under the circumstances 

 illustrated by these testing situations, it would be correct to code in Field V all the time-to-evaluation 

 values (i. e. , "double code" all the values) which correspond to those evaluations coded by that single 

 Field Y symbol. Unfortunately, double coding is limited in Field V, due to inherent difficulties in 

 mechanical sorting and interpretation when certain symbols are combined. Double coding is permitted 

 in Field V only when the two or more "times to evaluation" are in the same group of symbols (of the 

 four groups in the Code). Double coding of symbols from two groups is not possible, as illustrated 

 by the two values, 1-1/2 minutes and 7-1/2 minutes, for which the code symbols would be 9 (Group 1) 

 and B (Group 2). The punches for these two symbols on the IBM card would be 9, 2, and the 12 zone 

 punch (2 combined with the 12 zone punch represents Symbol B). In interpreting this punching, there 

 is no way of knowing whether the 12 zone punch is meant to be combined with the 2 punch (= Symbol B) 

 or with the 9 punch (= Symbol I). In most cases, however, when it would be desirable to double code 

 in Field V, double coding is not frustrated by this limitation, because in any single type of test, the 

 times of evaluation are apt to occur within only one of the four symbol groups. When the situation 

 arises in which double coding of Field V is prohibited due to the symbols being members of different 

 symbol groups (of the four groups in the Code), two lines should be constructed, identical except for 

 the coding in Field V which will record in one line the shortest time to evaluation and in the other line 

 the longest time to evaluation. 



Double coding Field V in the same code line in which another field (e. g. , Field P, duration of 

 administration) is double coded is not impossible, but is restricted in that the coding of one of the 

 double-coded fields must bear reciprocal relations to the other, as described in Division 6 of Specific 

 Directions and Explanations of Field P (illustrated there with Fields P and M). 



When Field V is double coded, both symbols are punched in Column 67 on the same IBM card. 

 Field V is not a filing field (see Division 7 above), so no problem exists relative to filing the card by 

 one or the other of the two symbols in the column. Having a zone punch combined with two numerical 

 punches in the same column would add complexity to any mechanical sorting in Field V, however. This 

 could be avoided by punching two cards when Field V is double coded with two letter symbols, but so 

 few occasions are apt to occur for double coding with two letter symbols in the field and the machine 

 sorting of Field V is so infrequent or even improbable, the CBCC has not prepared two cards with the 

 Field V double coding punched separately. 



- 170 



