Since you ask Dave,
The research I have been working on for the last 30 years which includes fieldwork in Holderness and substantial cross referencing with those references available from other collectors and literary sources. This is something that has been going on for some time. The use of biological statistical methods was suggested by Chris Cawte and has thrown up, among other things, a dance tradition that was not known to exist, a distribution map that indicates not only a transition from one form to another but also a comparative aging of the morris and the sword dances together with other dance traditions which, in the areas of east and west yorkshire exist along side each other. Couple this with the work done by numerous agencies on settlement patterns in the same area and some surprising things leap out. I say again, the problem is the word 'morris' which has been used as a 'catch-all' term for a series of older and, of course, younger dance traditions across the whole country.
cheers