broken but interesting branch  in which the parent poymorphic classes are made into one-many relationships with the child classes, ultimately this seems to be a poor design decision because although less redundant it would make the joins from e.g. data_set out to the data tables more confusing because it would be a composite key between data_set and some other attribute stored in one of the subclassed experiment classes
Merge branch 'master' of github.com:steve-federowicz/om