When measuring customer experience, companies need to focus on customers' perceptions of their interaction with the firm. That's because experiences are subjective — customers' perception is their reality. Just knowing how customers feel about an interaction isn't enough, though. Tracking the who, what, when, and where of an experience helps uncover the underlying cause of what customers felt. Firms also need to track what customers do after an experience in order to show the business value of better experiences. Companies looking to measure customer experience should organize the data they have today into three buckets: what happened, customers' perception of what happened, and what customers did based on their perception. Grouping metrics this way will make the data easier to understand and highlight gaps in the data that need to be filled.