1. An apparatus for specifying one or more rules for processing data included in one or more fields of each element of a plurality of elements of a dataset, the apparatus including: a user interface module configured to render a plurality of user interface elements associated with a respective condition, the user interface elements including one or more first subsets of the user interface elements, at least some subsets of the one or more first subsets associated with an input value derived from at least one field of an element of the plurality of elements of the dataset, and multiple second subsets of the user interface elements, each user interface element of one or more of the multiple second subsets configured to receive user input associated with a respective condition; and a processing module, including at least one processor, configured to apply conditions to at least a first element of the dataset based on user input received from at least some of the user interface elements, in response to receiving user input for a first user interface element associated with a first field, where applying the conditions includes compiling a selected portion of a specification of the rules to generate instructions for applying one or more selected conditions associated with fewer than all of the user interface elements, the selected conditions including at least a condition associated with the first user interface element, and executing the generated instructions and providing feedback associated with a result based on applying the condition associated with the first user interface element to data included in the first field of the first element.