1. At a computer system including a display device and a user-interface architecture, a method for creating a commingled data-centric application, the method comprising: an act of the user-interface architecture receiving user-entered data commands for creating a data model including at least one or more data fields; an act of the user-interface architecture receiving user-entered rule commands indicating a business logic rule is to be associated with one or more selected data fields among the one or more data fields; an act of the user-interface architecture converting the user-entered rule command into a meta-data format that can be associated with the one or more selected data fields in a commingled data-centric application such that user-interface architecture abstracts the meta-data format from the user and thereby relieves the user from having to know the meta-data format; and an act of the user-interface architecture associating the meta-data format of the business logic rule with the one or more selected data fields to commingle the data model with the business logic rule within a commingled data-centric application.