A while back, Andreas asked that the facility for resampling (with replacement) the entire dataset be (a) documented, and (b) make reversible. In current CVS and Windows snapshot I have implemented (b). You can do, for example, dataset resample 100 # do stuff dataset restore The "dataset restore" command will attempt to re-establish the original dataset. Modified values of scalar variables and newly added scalars will be carried back, but any series added while resampled will be discarded (as will any changes to pre-existing series values). I'm not going to document this for the 1.7.4 release because I consider it experimental. Meanwhile I'd appreciate if people can test this feature. Here's a little sample script: open data4-1 scalar x = 4 ols 1 0 2 # over-sampling: the original dataset has n = 14 dataset resample 200 genr newseries = normal() ols 1 0 2 ess = $ess x = 5 dataset restore print -o # note: 'newseries' is gone print x ess # new scalar values are preserved Allin.