The AARRR Pirate Metrics Framework is a popular way to measure the success of a user experience. The Pirate Metric acronym stands for Acquisition, Activation, Retention, Referral, and Revenue, and is dubbed the "pirate" framework for the similarity to a pirate's "arrr matey". Each of these metrics can help you track the progress of your user experience and determine whether or not it is successful.

Quantitative research focuses on how people behave and what actions they take through the gathering and analysis of data.