An exploratory case study research design was followed to explore and categorize 23 pre-service physics teachers’ understanding in the fields of superconductivity and nanotechnology at the Sultan Qaboos University in Oman. To elicit their responses, a five-stage categorical framework analysis was used. The five stages included identification of the thematic framework, familiarization, coding, placing the categories on a chart and finally, interpretation. A conceptual survey test (Conceptual Survey of Superconductivity and Nanotechnology) was administered to the pre-service physics teachers to form four independently homogenous ability focus groups. This was followed by focus group discussions whose data were analyzed to group their conceptions in both the epistemological as well as ontological categories. From the focus group discussions, six categories were considered from previous studies, namely; lateral alternative conceptions, ontological conceptions, naïve physics, Ohm’s p-primes, mixed conceptions and loose ideas. Since this was a pre-instructional study, naïve physics ideas and lateral alternative conceptions were dominant. Naïve physics refers to the untrained student or human perception of various physical phenomena while lateral alternative conception refers the misconceptions individuals have on ideas that may be inconsistent with scientifically acceptable facts. Findings indicate that the pre-service teachers’ conceptions deviated from canonical scientific concepts, are diversified and inconsistent. The knowledge on pre-instructional conceptions will influence the development of evidence-based pedagogy, which is fundamental to the development of an effective physics education curriculum. / Institute for Science and Technology Education (ISTE) / M. Sc. (Physics Education)