ABSTRACT
EXAMPLE 1: In pregnancy monitoring, the week of pregnancy jc is often estimated using ultrasound fetal bone measurements Y. In Oman and Wax
(1984, 1985), the two bone measurements F (femur length) and BPD (biparietal diameter) are quadratically related to week of pregnancy W , giving the model
EXAMPLE 2: In agricultural science, Racine-Poon (1988) studied the degradation profile of an agrochemical using the model
where x is the concentration of the chemical in a pot of soil and Y is the weight of a sensitive plant grown in the pot for a given period of time.
