A computerized method of creating a user model, comprising: 1) Providing one or more software component collections containing software components. Each of the software components is associated with a single attribute and has: a. An attribute generation engine for calculating an attribute data. b. An attribute repository which stores the attribute data. c. An output object which outputs the attribute data to another of the plurality of software components. d. A metadata field which holds an identifier relating to the respective software component. 2) Selecting by a developer, a subset of software components. 3) Defining by the developer, a plurality of data links mapping data flow among the members of the subset. 4) Generating a user model based on the subset and the data links. 5) Outputting the user model.