FIELD M 

 Columns 45 and 46 



FIELD N 

 Columns 47 and 48 



DOSAGE 



FIELD M- -PROPORTIONS OF TEST COMPOUND AND DILUENT : 

 I. E. , CONCENTRATION OF TEST COMPOUND 

 ADMINISTERED TO THE TEST ORGANISM OR HOST 



FIELD N--(l) QUANTITY OF PURE TEST COMPOUND ADMINISTERED; 

 (2) PROPORTIONS OF PURE TEST COMPOUND 

 PER UNIT OF TEST ORGANISM OR OF HOST 



Organization 



Fields M and N each have code symbols which consist of two units. These symbols are 

 recorded by the CBCC in IBM punched card Columns 45 and 46 (Field M) and 47 and 48 (Field N). The 

 first code unit in each field (Columns 45 and 47) designates the unit of measure in which the quantity 

 is expressed (e. g. , in Field M, parts per million, molar concentration, etc. , and, in Field N, micro- 

 grams, milligrams, etc. ). The second code unit of each field (Columns 46 and 48) indicates the actual 

 quantitative value (e. g. , in Field M, the number of parts per million, the number of millimoles per 

 cubic centimeter, etc. , and, in Field N, the number of micrograms or milligrams, etc. ). 



Thus, in both Fields M and N, a dosage is expressed by indicating (1) the unit of measure and 

 (2) the measure or quantity itself. Providing code symbols for the first is merely a matter of assigning 

 sequential numbers or letters to each unit of measure, such as Symbol 1 for parts per million, Symbol 2 

 for molar concentration, etc. The second, however, is not so simple as it may superficially appear. 

 It is not practical to code specifically the numerical quantitative values themselves; therefore, code 

 symbols must be assigned to represent ranges of quantitative values, such as a symbol which represents 

 a range of 1 ppm to 5 ppm and another symbol for 5 ppm to 25 ppm, etc. Having made a definition for 

 a symbol, such as > 1-5 ppm (i. e. , any number of ppm more than 1 up to and including 5 ppm), it is 

 thereby impossible to distinguish by code 2 ppm from 4 ppm; it is only possible, by code, to distinguish 

 between ranges , so that a dosage can be indicated only as being in the range of > 1-5 ppm or > 5-25 

 ppm, etc. Defining these ranges resolves itself into a problem of determining reasonable limits of each 

 range. This is intimately linked with the coding field used for recording evaluations of test results 

 (Field Y). Since the difference between evaluations is sometimes solely a reflection of the amount of 

 test compound administered, it is important that the ranges not be so broad that this difference in 

 responses can not be explained in code by appropriate dosage symbols in Field M and/or N. Consider, 

 as an illustration, a given test compound which caused a given response, but at a very low or insignif- 

 icant degree at a dosage of 0. 1 units; not until 50 units was administered was the response optimal. 

 Since the dosage value for this data will be coded as a range in which lies the smallest dose causing 

 the highest response (50 units), it is important that the range in which 50 units lies is narrow enough 

 so that doses causing less response or no response are not in the same range. If the range covered by 

 a single code symbol were 1-100 units, for example, the fact that the most effective dose was 50 units, 

 whereas 20 units, 5 units, 1 unit, etc. , were less effective or totally ineffective, could not be dis- 

 tinguished by code. All such a code symbol would indicate would be that somewhere between 1 and 100 

 units, the test compound produced the response to the degree indicated in Field Y. However, if the 

 definition of a code symbol were a range of only 30-60, the use of that symbol would indicate at least 

 that somewhere between 30 and 60 was the dose producing the response of the degree indicated in 

 Field Y and that below 30 the response occurred at a lower degree or not at all. Thus, the more narrow 

 the range represented by each code symbol, the more precise can be the coding of dosage administered 

 producing the response to the degree coded in Field Y. 



Because of the relationship between the dosage fields (Fields M and N) and the evaluation field 

 (Field Y) and because in Field Y the symbols available for evaluation coding are only digits and 1-9, 

 the only symbols correspondingly permitted in Columns 46 and 48 of Field M and N are and 1-9. The 

 value scales are divided, therefore, into 9 (or rarely 10) consecutive ranges. (Reference should be 



- 82 - 



