how to compensate for when they change appearance slightly. We should also provide it
with at least a few examples of people who are not allowed into the secret area, so we can be
sure it will refuse admittance to non-authorised staff. This type of problem for a learning
system is known as a classification problem, the answer it provides classifies each input
into different categories. Another problem would be to predict the weight in kilograms of
the person from a photograph; this provides a real-valued output, for example 80.53kg or
67.901kg. This is a regression problem.