POWER LAW (Nordling, 1953; Armitage and Doll, 1954) | fa = bDk; log(fa) = k log(D) + log b |
PROBIT (Bliss, 1939; Finney, 1947, 1952, 1971) | fa = where Y = (log D - log Dm)/σ |
LOGIT (Berkson, 1946; Thompson, 1947) | fa = 1[1 + e-(α + βlog D)] |
The median-effect equation of the MASS-ACTION LAW (Chou, 1974, 1976) | fa/fu = (D/Dm)m; log[(fa)-1 - 1]-1 = m log (D) - m log(Dm) |
D, dose; Dm, median-effect dose; m, kinetic order; fa, fraction affected; fu, fraction unaffected; σ2, variance; Y (PROBIT – 5) or normal equivalent deviate; a, k, α, and β, undefined constants