This chapter explores the specialised terminology used in person-reported outcome measures (PROMs) and person-reported experience measures (PREMs), for questionnaire design and scoring schemes. PROMs and PREMs rely on terms, many derived from psychology and market research, which describe various components like items, options, scales, and scoring systems. Understanding these terms and using them correctly is vital for designing effective, readable questionnaires that elicit reliable data from diverse populations. Core concepts include the distinction between measures, items, and domains, as well as the structure of response options such as ordinal or interval scales. The chapter also addresses challenges in demographic data collection, readability, and translation. Scoring systems, including raw, transformed, normative, and preference-weighted scores, help interpret results. By defining these terms, this chapter establishes a shared language for researchers and practitioners, enabling consistent and meaningful implementation of PROMs and PREMs in healthcare to assess outcomes and improve patient-centred care.