Comprehensive Assessment of the Performance of Deep Learning Classifiers
  Reveals a Surprising Lack of Robustness
Michael W. Spratling
Reliable and robust evaluation methods are a necessary first step towards
developing machine learning models that are themselves robust and reliable.
Unfortunately, current evaluation protocols typically used to assess
classifiers fail to comprehensively evaluate performance as they tend to rely
on limited types of test data, and ignore others. For example, using the
standard test data fails to evaluate the predictions made by the classifier to
samples from classes it was not trained on. On the other hand, testing with
data containing samples from unknown classes fails to evaluate how well the
classifier can predict the labels for known classes. This article advocates
bench-marking performance using a wide range of different types of data and
using a single metric that can be applied to all such data types to produce a
consistent evaluation of performance. Using such a benchmark it is found that
current deep neural networks, including those trained with methods that are
believed to produce state-of-the-art robustness, are extremely vulnerable to
making mistakes on certain types of data. This means that such models will be
unreliable in real-world scenarios where they may encounter data from many
different domains, and that they are insecure as they can easily be fooled into
making the wrong decisions. It is hoped that these results will motivate the
wider adoption of more comprehensive testing methods that will, in turn, lead
to the development of more robust machine learning methods in the future.
  Code is available at:
\url{https://codeberg.org/mwspratling/RobustnessEvaluation}