Kinematic model for a CME with constant acceleration 2 m s^-2 and initial velocity 300 km s^-1, and two data simulations of how the resulting profiles for different scatters on the height-time measurements (top panels) behave when 3-point Lagrangian interpolation is used to derive the velocities (middle panels) and accelerations (bottom panels). Both simulated cases were produced by adding scatter to the height measurements, via a normally-distributed random number generator with a standard deviation of 10% of the model height at each time-step. The different instances of scatter shown here produce completely opposing trends in the accelerations, with the errorbars failing to appropriately overlap the model, therefore belying the true trend.