Self-observation, an umbrella term for a number of methods associated with first-order accounts of mental activity (e.g. introspection) and first-person reporting, has been a part of psychology’s investigative procedures since the inception of the discipline. It remains an integral, albeit contested, tool for psychologists to use across essentially every sub-field. In areas such as phenomenology, memory research, psychological assessment, and ethnography, among others, self-observation has been deployed to access information not readily acquired through alternative methods. Other names for introspective methods include self-report, retrospection, inner perception, and self-reflection.