| A | absorbance for computing %reduction in bacte- rial growth from turbidimetric readings.
 | 
| b | slope of the straight line relating response (y)to log-dose (x)[Equations 2b,4,5,6].
 | 
| c | constant for computingM¢with Equations 8 and 10.
 | 
| c¢ | constant for computing Lwith Equations 26 and 29.
 | 
| ci | constant for computingM¢when doses are spaced as in Table 8.
 | 
| c¢i2 | constant for computing Lwhen doses are spaced as in Table 8.
 | 
| C | term measuring precision of the slope in a confidence interval [Equations 27,28,35,36].
 | 
| c2 | statistical constant for testing significance of a discrepancy [Table 9].
 | 
| cM2 | c2testing the disagreement between different estimates of log-potency [Equations 39,40].
 | 
| eb | eifrom row bin Tables 6to 8. | 
| eb¢i | multiple of S(x bar(x))2[Table 5;Equation 6]. | 
| ei | sum of squares of the factorial coefficients in each row of Tables 6to 8.
 | 
| eq | eifrom row qin Tables 6to 8. | 
| f | number of responses at each dosage level of a preparation;number of replicates or sets.
 | 
| fS | number of observations on the Standard. | 
| fU | number of observations on the Unknown. | 
| F1to F3 | observed variance ratio with 1to 3degrees of freedom in numerator [Table 9].
 | 
| G1,G2,and G3 | relative gap in test for outlier [Table 1]. | 
| h | number of Unknowns in a multiple assay. | 
| h¢ | number of preparations in a multiple assay, including the Standard and hUnknowns;i.e.,
 h¢=h+1.
 | 
| i | interval in logarithms between successive log-doses,the same for both Standard
 and Unknown.
 | 
| k | number of estimated log-potencies in an average [Equation 24];number of treatments or doses
 [Table 4;Equations 1,13,15,16];number of
 ranges or groups in a series [Table 2];number
 of rows,columns,and doses in a single Latin
 square [Equations 1a,16a].
 | 
| L | length of the confidence interval in logarithms [Equations 24,26,29,38],or in terms of a
 proportion of the relative potency of the
 dilutions compared [Equations 31,33].
 | 
| Lc | length of a combined confidence interval [Equations 42,43].
 | 
| Lc¢ | length of confidence interval for a semi-weighted mean bar(M)[Equation 48].
 | 
| LD50 | lethal dose killing an expected 50%of the animals under test [Equation 2c].
 | 
| M | log-potency [Equation 2]. | 
| M¢ | log-potency of an Unknown,relative to its assumed potency.
 | 
| bar(M) | mean log-potency. | 
| n | degrees of freedom in an estimated variance s2or in the statistic tor c2.
 | 
| n¢ | number of Latin squares with rows in common [Equations 1a,16a].
 | 
| N | number;e.g.,of observations in a gap test [Table 1],or of responses yin an assay
 [Equation 16].
 | 
| P | probability of observing a given result,or of the tabular value of a statistic,usually P=0.05or
 0.95for confidence intervals [Tables 1,2,9].
 | 
| P* | potency,P*=antilog Mor computed directly. | 
| R | ratio of a given dose of the Standard to the corresponding dose of the Unknown,or assumed potency
 of the Unknown [Equations 2,30,33].
 | 
| R* | ratio of largest of kranges in a series to their sum [Table 2].
 | 
| s =Öbar(s)2 | standard deviation of a response unit,also of a single estimated log-potency in a direct assay
 [Equation 24].
 | 
| s2 | error variance of a response unit. | 
| Si | a log-dose of Standard [Tables 6,7]. | 
| S | the sum of. | 
| t | Student's tfor ndegrees of freedom and probability P=0.05[Table 9].
 | 
| T | total of the responses yin an assay [Equation 16]. | 
| T¢ | incomplete total for an assay in randomized sets with one missing observation [Equation 1].
 | 
| T1 | S(y)for the animals injected with the Standard on the first day [Equations 18,36].
 | 
| T2 | S(y)for the animals injected with the Standard on the second day [Equations 18,36].
 | 
| Ta | Tifor the difference in the responses to the Standard and to the Unknown [Tables 6to 8].
 | 
| Tab | Tifor testing the difference in slope between Standard and Unknown [Tables 6to 8].
 | 
| Taq | Tifor testing opposed curvature in the curves for Standard and Unknown [Tables 6to 8].
 | 
| Tb | Tifor the combined slope of the dosage-response curves for Standard and Unknown [Tables 6to
 8].
 | 
| Tb¢ | S(x1Tt)or S(x1y)for computing the slope of the log-dose response curve [Equations 10,23,
 28].
 | 
| Ti | sum of products of Ttmultiplied by the corresponding factorial coefficients in each
 row of Tables 6to 8.
 | 
| Tq | Tifor testing similar curvature in the curves for Standard and Unknown [Tables 6to 8].
 | 
| Tr | row or set total in an assay in randomized sets [Equation 16].
 | 
| Tr¢ | incomplete total for the randomized set with a missing observation in Equation 1.
 | 
| Tt | total of fresponses yfor a given dose of a preparation [Tables 6to 8;Equations 6,13,
 14,16].
 | 
| Tt¢ | incomplete total for the treatment with a missing observation in Equation 1.
 | 
| Ui | a log-dose of Unknown [Tables 6to 8]. | 
| v | variance for heterogeneity between assays [Equation 45].
 | 
| V=1/w | variance of an individual M[Equations 44to 47]. | 
| w | weight assigned to the Mfor an individual assay [Equation 38],or to a probit for computing an
 LD50[Equations 2a,2b].
 | 
| w¢ | semi-weight of each Min a series of assays [Equations47,48].
 | 
| x | a log-dose of drug in a bioassay [Equation 5]; also the difference between two log-threshold
 doses in the same animal [Equation 12].
 | 
| x* | coefficients for computing the lowest and highest expected responses YLand YHin a log-dose
 response curve [Table 4;Equation 3].
 | 
| x1 | a factorial coefficient that is a multiple of (x bar(x)) for computing the slope of a straight line
 [Table 5;Equation 6].
 | 
| bar(x) | mean log-dose [Equation 5]. | 
| bar(x)S | mean log-dose for Standard [Equation 9]. | 
| bar(x)U | mean log-dose for Unknown [Equation 9]. | 
| X | log-potency from a unit response,as interpolated from a standard curve [Equations 7a,7b,19].
 | 
| XM | confidence limits for an estimated log-potency M [Equations 25,30].
 | 
| XP* | confidence limits for a directly estimated potency P*(see Digitalisassay)[Equation 33].
 | 
| y | an observed individual response to a dose of drug in the units used in computing potency and the
 error variance [Equations13to16];a unit
 difference between paired responses in 2-dose
 assays [Equations17,18].
 | 
| y1...yN | observed responses listed in order of magnitude, for computing G1,G2,or G3in Table 1.
 | 
| y¢ | replacement for a missing value [Equation 1]. | 
| bar(y) | mean response in a set or assay [Equation 5]. | 
| bar(y)t | mean response to a given treatment [Equations3,6].
 | 
| Y | a response predicted from a dosage-response relationship,often with qualifying subscripts
 [Equations 3to5].
 | 
| z | threshold dose determined directly by titration (see Digitalisassay)[Equation 11].
 | 
| bar(z) | mean threshold dose in a set (see Digitalisassay) [Equations 31,32,33].
 |