© 1977 by Biometrika Trust
Optimal use of extraneous information concerning a nuisance parameter
Unité de Recherches Statistiques, Institut National de la Santé et de la Recherche Médicale Villejuif, France
Suppose that N experiments can be carried out. One type of experiment provides observations, Y, depending on
, the parameter of interest and ß a nuisance parameter. The other type provides observations, Z, depending on ß and
. How should the N experiments be divided between the two types to estimate
optimally? The existence and uniqueness of an optimal allocation is proved and a method of calculation is provided. In the particular case of ß being scalar, the optimal allocation is given explicitly, and is not necessarily the simple solution consisting of performing only experiments of the first type. In this case, an observation Z may provide additional information concerning
which is more useful than a further observation Y. An application to estimation from truncated data is described and further generalizations are considered.
Key Words: Nonlinear design Nuisance parameter Optimal experiment Truncated data