This paper reports a multi-national, multi-institutional study to investigate Computer Science students' understanding of software design and software design criteria. Student participants were recruited from two groups: students early in their degree studies and students completing their Bachelor degrees. Computer Science educators were also recruited as a comparison group. The study, including over 300 participants from 21 institutions in 4 countries, aimed to understand characteristics of student-generated software designs, to investigate student recognition of requirement ambiguities, and to elicit students' valuation of key design criteria. The results indicate that with increases in education, students use fewer textual design notations and more graphical and standardized notations and that they become more aware of ambiguous problem specifications. Yet increased educational attainment has little effect on students' valuation of key design characteristics.