

\subsection{\bf Particular Robust Estimates for}
\subsection{\bf Likelihood---Huber}

\begin{slide}
\begin{itemize}
\item Now we invent a function $\Psi$ which is less sensitive to
$x^{(i)}$'s far from the mean than $(x^{(i)}-\mu)$.

\item In Huber's method, one sets
\begin{tabular}{rclcr}
$\Psi (z)$ & = & $z$ & for & $|z| \le z_c$ \\
and $\Psi (z)$ & = & $z_c$ & for & $z>z_c$ \\
& = & $-z_c$ & for & $z> -z_c$
\end{tabular}

\vspace*{10pt}
\centerline{\psfig{figure=fig26.phys.ps,clip=true,width=5.5in}}
\vspace*{10pt}
\end{itemize}
\end{slide}

