Abstract: User interface techniques facilitating computer system coding and data transformations are provided. In some aspects of the invention, a data transformation facilitating tool is provided, which allows a user to perform complex, multi-step transformations of data held within a set of cells of a spreadsheet, without using additional cells of the spreadsheet. In other aspects of the invention, a 2-way coding and presentation assessment tool is provided, which allows a user to alter underlying software code for a spreadsheet program by manipulating a graphical component of the spreadsheet program, and vice-versa, using a parallel coding window, which is simultaneously presented to the user.