Computation times (in seconds) for proposed Bayesian variable selection procedure, using empirical Bayes to select between two priors (M= 2) and to set the prior strength parameter λ (optimisation performed over ten values of λ). Results shown for varying values of dmax(maximum number of predictors allowed in a model) and p (total number of predictors), for both a linear model without interaction terms and a linear model with interaction terms. (Data and model priors generated using random numbers and results are averages over three iterations. Computation performed on a standard single-core personal computer; 1.6GHz, 2GB RAM. ‘-’ denotes a (p,dmax) regime where the procedure failed due to insufficient memory).