This paper proposes a novel framework for systematic reviews, the "conceptual systematic review" (CSR), incorporating elements of content analysis that often implicitly precede synthesising research but are rarely made explicit. We argue that a CSR has the possibility to conceptually map a "tangled term," to prepare systematic reviews, to advance interdisciplinary communication, and to offer guidance in tangled fields of scientific discourse. The proposed methodological framework involves a six-stage procedure aimed at systematically unravelling tangled terms through the deductive--inductive coding of a systematically retrieved literature corpus, thereby going beyond the quantitative synthesis of research findings. We call the elements of such a framework "heuristics," "classifications," and "systematics"; they provide insight into the quality of term disentanglement and can be viewed hierarchically: heuristics do not (necessarily) satisfy any quality criteria, classifications adhere to "analytical quality criteria," and systematics also meet "empirical quality criteria." The six quality criteria through which the quality of a CSR can be made explicit are introduced to allow for professional scrutiny and critique. It is argued that making conceptual elements of systematic reviews explicit is especially relevant in the field of educational research. Finally, we discuss the relation of the CSR to similar methods and address weaknesses in the proposed framework.