Students plot position and velocity graphs as the path of the particle.

"Student difficulties in connecting graphs and physics: Examples from kinematics," L.C. McDermott, M.L. Rosenquist and E.H. van Zee, Am. J. Phys., 55, 503-513 (1987).

Students don't know what quantity in a graph will answer the question (coordinate, slope, or area).

"Student difficulties in connecting graphs and physics: Examples from kinematics," L.C. McDermott, M.L. Rosenquist and E.H. van Zee, Am. J. Phys., 55, 503-513 (1987).

Students have difficulty relating real world motions to a graph and vice-versa.

"Student difficulties in connecting graphs and physics: Examples from kinematics," L.C. McDermott, M.L. Rosenquist and E.H. van Zee, Am. J. Phys., 55, 503-513 (1987).

"Student difficulties with graphical representations of negative values of velocity," F. M. Goldberg and J. H. Anderson, Phys. Teach. 27, 254-260 (1989).

Velocity must be positive, plotted above the time axis.

"Student difficulties in connecting graphs and physics: Examples from kinematics," L.C. McDermott, M.L. Rosenquist and E.H. van Zee, Am. J. Phys., 55, 503-513 (1987).

"Student difficulties with graphical representations of negative values of velocity," F. M. Goldberg and J. H. Anderson, Phys. Teach. 27, 254-260 (1989).

A positive slope for a negative velocity means the object is speeding up.

"Student difficulties with graphical representations of negative values of velocity," F. M. Goldberg and J. H. Anderson, Phys. Teach. 27, 254-260 (1989).