Interpretation and construction of graphs are central to the study of physics and to performance in physics. In this paper, I explore the interpretation and construction processes called upon in questions with a graphical component, in Western Australian Physics Tertiary Entrance Examinations. In addition, I list errors made by students as reported by examiners and offer explanations for the errors. Outcomes of the inquiry are the identification of sources of challenge in the graphing questions, including requirements to calculate gradient and analyse experimental data. I also identify question structures that could be barriers to students' understanding the examination questions. The micro-analysis of graphing in one jurisdiction can inform assessment of high-school physics in general.