1. A method comprising: displaying, by one or more computer systems, a user interface comprising a cause region and an effect region; displaying, by the one or more computer systems, a plurality of dimension objects and a plurality of measure objects adjacent to the cause region and the effect region, respectively, each dimension object representing an input category associated with an input quantity that contributes to a total quantity in a data set, each measure object representing an output category associated with an output quantity based on at least one quantity of at least one input category represented by at least one dimension object; detecting, by the one or more computer systems, a first input to move a first dimension object into the cause region, the first dimension object representing a first input category associated with a first input quantity; detecting, by the one or more computer systems, a second input to move a first measure object into the measure region, the first measure object representing a first output category associated with a first output quantity; in response to detecting the first input and the second input: displaying, by the one or more computer systems, the first dimension object in the cause region, displaying, by the one or more computer systems, the first measure object in the effect region, determining, from the data set and by the one or more computer systems, the first output quantity based on the first input quantity from the total quantity in the data set, and displaying, by the one or more computer systems, a result representing the first output quantity in the first measure object.