Diagnostic analytics to identify anomalies/outliers

Often the first step in diagnostic analytics is to look for and identify unusual, unexpected results or transactions.

Benford's law defined

Benford's law is the principle that in any large, randomly produced set of natural numbers, there is an expected distribution of the first, or leading, digit with there being more 1s, 2s next most, and down successively to number 9. If are we working with a data set and we observe that the data doesn't follow Benford's law, we would say that we have an anomaly in our data and we would investigate the reason(s) for that anomaly.