There is a lack of commonly used terminology to classify non-state private actors in education. This presents challenges for research. This chapter considers the implications of hybridity on definitional exercises. It presents pre-determined definitions that were found in two literature reviews framing a study on non-state private actors financing education initiatives in Asia, with a focus on private foundations and impact investors. The literature reviews revealed serious definitional inconsistencies in the conceptual literature as well as in how terms were used by actors themselves. Inconsistencies were aggravated by incomplete publicly available data on organisational self-identification and by differing regulatory contexts. The chapter provides an inductively derived working typology on organisational forms of private foundations, impact investors, and other actors relevant to the study. It argues that inductive characterisations may be better-suited to classify organisational forms than regulatory definitions, particularly for hybrid actors or those using hybrid strategies. This is heightened in comparative or global studies.