Methods and apparatus, including computer program products implement techniques for processing experimental data according. An input specifies a set of variable definitions according to a variable definition template for defining a set of variables of a plurality of variable types usable in experiments of a pre-defined experiment class. Data from an experiment of an experiment type is received. A first representation of the data is stored in a format defined according to the plurality of variable types. A second representation of the data, derived from the first representation, is presented in a format defined according to the set of variable definitions. The variable definition template is referenced in the pre-defined experiment class. The data includes a plurality of values corresponding to variables defined in the set of variable definitions.