Educational technology terminology is messy. The same meaning is often expressed using several terms. More confusingly, some terms are used with several meanings. This state is unfortunate, as it makes both research and development more difficult. Terminology is particularly important in the case of personalization techniques, where the nuances of meaning are often crucial. We discuss the current state of the used terminology, highlighting specific cases of potential confusion. In the near future, any significant unification of terminology does not seem feasible. A realistic and still very useful step forward is to make the terminology used in individual research papers more explicit.