The mapping of different semantic and syntactic elements on the acquisition and practice of text-editing skill is used to test predictions from a production system model of skill development. Five text editors that use specific or general procedures that either obey a joint or a disjoint syntax have been designed and tested. Joint syntax and disjoint syntax, respectively, refer to whether defining the operation and the object in a procedure is done in a single or in two different steps. Tests of the editors were carried out using a set of varied tasks presented in two different serial task orders. Results showed that specific procedures are not necessarily faster to use than general ones for simple tasks, but general ones are faster for complex ones. Moreover, specific procedures are more prone to forgetting, as users consulted the help facilities more often. Users of joint editors consulted the help menu less often but for a longer time than users of disjoint editors. They also experienced a greater workload. It is suggested that joint and disjoint editors differ according to the way task parameters must be provided to the procedures. Finally, all measures were sensitive to serial task orders. The production system model of skill development is shown to provide an accurate explanation of group differences and of serial task order effects through strength accumulation, number of executed cycles, and cognitive operators.