Here's a fascinating article on learning words in pairs, by Rob Waring of Notre Dame Sheishin University. (Follow the links at the bottom of his article for more vocabulary resources).

The article begins with the shortcomings of 'list learning', then moves on to the advantages of 'pair learning' (learning words as a pair only - a foreign word and your mother tongue equivalent, or some other prompt such as a picture), and how to do that well. He describes a box system similar to the original VOLATS, whereby each word card moves back through the box as the learner becomes more familiar with it. A 'relearning schedule' illustrates the need for re-testing at increasing intervals.

So much in tune with the thinking behind VOLATS, Archie would have been delighted.

I particularly like his point that vocabulary learning works best when done in regular, small doses; and that the more you learn, the easier it becomes. Both very encouraging!