[78-L] Can anybody tell me who decided which recordings would be on each side of a two-sided record?

[Eric]

I have always wondered who decided, prior to 1930, which recordings would be 
packaged together on records with two sides.  Did the record companies have 
formulas?  Were the companies trying to promote side B by having it next to 
side A?
Did the companies have an entire department, one person or both in charge of 
such decisions?  Any help would be greatly appreciated.