  In many practical tasks it is needed to estimate an effect of treatment on
individual level. For example, in medicine it is essential to determine the
patients that would benefit from a certain medicament. In marketing, knowing
the persons that are likely to buy a new product would reduce the amount of
spam. In this chapter, we review the methods to estimate an individual
treatment effect from a randomized trial, i.e., an experiment when a part of
individuals receives a new treatment, while the others do not. Finally, it is
shown that new efficient methods are needed in this domain.
