This document discusses customer experience metrics and measurement. It introduces the concept of a "Red Headed Step Child" metric, which refers to a metric that is not well understood or adopted by an organization. Over multiple volumes, it explores how to develop meaningful CX metrics from the bottom up by starting with individual transactions and aggregating data, choosing important metrics to measure, using statistical methods like regression and reliability analyses, combining qualitative and quantitative research, and ensuring metrics drive improvement through closed-loop follow up. The overall goal is to turn CX metrics from a "Red Headed Step Child" into meaningful measures that guide organizations.