This study characterized the variation in undergraduate physics students depictions of the basic concepts of Quantum Mechanics (QM) and extrapolated to possible instructional practice changes. The study was approached through in-depth interviews with 35 physics students from two Ethiopian governmental universities after exposure to the traditional QM course for one-third of a semester. Interview responses were analyzed using phenomenographic approach where a picture of students' depictions was established for each quantum concept by expounding the given responses.

The description categories were separately constructed for each concept, and overall, it was found that naive, quasi-classical ontology and/or variants of classical ways of visualization are dominant in students' responses. For example, students' depictions of the photon concept could be described with three distinct categories of description (a) classical intuitive, (b) mixed model and (c) quasi-quantum model. Similarly, it is possible to establish three categories of students' depictions of matter waves (a) classical and trajectory-based, (b) an intricate blend of classical and quantum and (c) incipient quantum model. Likewise, students' depictions of uncertainty principle can be described as: uncertainty as (a) classical ignorance, (b) measurement disturbance and (c) a quasi-quantum principle.

Most students did not have enough knowledge to depict the basic concepts of QM properly; they were influenced by the perspective of classical physics and their perceptions in making explanations about QM; and they also applied mixed ideas of their classical model and the newly introduced QM. These results are also supported by the findings of previous studies in similar domains. Findings from the study were used to guide the design of multiple representations-based instructions and interactive learning tutorials.  Theoretical and practical implications, as well as potential future considerations are drawn.