We compare two approaches to the predictive modeling of dynamical systems from
partial observations at discrete times. The first is continuous in time, where one uses
data to infer a model in the form of stochastic differential equations, which
are then discretized for numerical solution. The second is discrete in time,
where one directly infers a discrete-time model in the form of a nonlinear
autoregression moving average model. The comparison is performed in a special case
where the observations are known to have been obtained from a hypoelliptic
stochastic differential equation. We show that the discrete-time approach has
better predictive skills, especially when the data are relatively sparse in
time. We discuss open questions as well as the broader significance of the
results.