Abstract: In an embodiment of the invention, a tax preparation method is implementable in an electronic system coupled to an electronic device, which is, in turn, coupled to a display device. A web page displayable on the display device is served to the electronic device. The displayed web page includes a user interface, which, in turn, includes a tab bar, with a plurality of tabs. In each tab at least one accordion is present. In each of the accordions there preferably exists at least one text box for explaining or receiving tax information, having a title, an input box and a flyout, the flyout providing tax assistance information to a the user. Once a desired amount of the text boxes have been completed and a completed tax document has been developed, a tax return may be filed with a government agency.

Abstract: A method is provided of modifying a hierarchal cost model of a multi-component system over a time period of the model extending from a historical time to a future time, wherein the model is built from item cost indices, each of which is built from one or more commodity price indices created from market data. The model is stored in memory of a computer system that includes a processor, a user input device and a display. The method includes the steps of selecting an item from the model, selecting a time from the model time period (the selected item time), and inputting a user selected cost of the item for the selected time. The processor modifies the item price index to create a custom item price index based on the input item price, the selected item date, and the item's constituent cost indices, and stores the custom price index in the memory. The method may further include modifying the cost model to create a custom cost model based on the custom item price index, and storing the custom cost model in memory.