The feature engineering approach
The objective of feature engineering is to exploit the qualitative insight of humans in order to create better machine learning models. A human engineer usually uses three types of insight: intuition, expert domain knowledge, and statistical analysis. Quite often, it's possible to come up with features for a problem just from intuition.
As an example, in our fraud case, it seems intuitive that fraudsters will create new accounts for their fraudulent schemes and won't be using the same bank account that they pay for their groceries with.
Domain experts are able to use their extensive knowledge of a problem in order to come up with other such examples of intuition. They'll know more about how fraudsters behave and can craft features that indicate such behavior. All of these intuitions are then usually confirmed by statistical analysis, something that can even be used to open the possibilities of discovering new features.
Statistical analysis can sometimes turn...