\section{Conclusions}
\label{sec:conclusions}

We have presented a study of a novel concept for sampling
electromagnetic calorimetry; namely a calorimeter with
binary readout. This requires very fine granularity and
a high level of sensor integration to handle the very
large number of pixels which are required.

The overall performance of 
a simulated full scale binary ECAL 
based on the test sensor results has been shown to give 
a better resolution
for electromagnetic showers than an equivalent analogue
readout ECAL. The dominating issue for the resolution
is the algorithm for counting charged particles given
the pattern of pixel hits observed. This is sensitive to
the shower core density. The simulation has not been
verified at this fine granularity required for a binary
ECAL and so there is some uncertainty. Hence,
this will require real data from EM showers
at very fine granularity to understand the limiting
resolution of a binary ECAL.
