1. A computer-implemented method, comprising: a modular rule engine of a computerized tax return preparation application comprising instructions executed by a processor of a computer receiving runtime data of the electronic tax return, wherein respective fields for respective questions presented by the tax return preparation application are populated with respective data of the runtime data, determining which questions of the tax return preparation application remain unanswered after receiving the runtime data based at least in part upon the received runtime data and a data structure generated by transforming a first data structure of a pre-determined question-and-answer flow into a second data structure different from the first data structure, identifying unanswered questions within the second data structure that are free of pre-determined semantic dependency based at least in part upon an answer to at least one tax return preparation application question within the second data structure, wherein the unanswered questions are identified without reference to the first data structure, and selecting at least one identified unanswered question of the identified unanswered questions within the different, transformed data structure; and generating a non-binding suggestion based at least in part upon the selected unanswered question; and a modular interface controller of the computerized tax return preparation application receiving the non-binding suggestion as an input, and generating an interview screen that is presented to a user of the tax return preparation application through a display of the computer based at least in part upon the non-binding suggestion, the modular rule engine and the modular interface controller being loosely coupled to each other such that the non-binding suggestion generated by the modular rule engine does not control how the modular interface controller determines content of the interview screen.