Methods and apparatus are provided which solves the looping problem in structural documents, such as those defined by DOM, EDI and XML. The method and apparatus remove ambiguities by presenting a user with a hierarchical tree structure representation of the document allowing the user to select data grouping rules to be followed. The method and apparatus then automatically create a modified hierarchical tree structure based upon the user-defined rules. Rules can be input by the user using a rule table editor or by means of a graphical user interface.