

\subsection{\bf Robust Estimation---Motivation---II}

\begin{slide}
\begin{itemize}
\item Consider an example from physics where one observes mass
distribution with a Breit Wigner for a resonance, say,
plus ``small'' (usually large!) contributions to the probability
distribution (e.g., background which must be estimated as
polynomial/phase space) which must be parameterized in an ad hoc fashion.  

\vspace*{10pt}
\centerline{\psfig{figure=fig25.phys.ps,clip=true,width=5.25in}}
% \vspace*{10pt}

\item It is hard to evaluate distortion due to an incorrect
parameterization of these unknown contributions.

\item Obviously, the correct choice of method will depend on relative
size of signal (with known functional form), and background.
\end{itemize}
\end{slide}

