This paper considers what students attend to as they first encounter R[superscript 3] coordinate axes and are asked to graph y = 3. Graphs are critical representations in single and multivariable calculus, yet findings from research indicate that students struggle with graphing functions of more than one variable. We found that some students thought y = 3 in R[superscript 3] would be a line, while others thought it would be a plane. In creating their graphs, students attended to equidistance, parallelism, specific points, and the role of x and z. Students' use of these ideas was often generalised from thinking about the graphs of y = b equations in R[superscript 2]. A key finding is that the students who thought the graph was a plane always attended to the z variable as free. [For the complete proceedings, see ED583608.]