Developing decision-making skills of a user through practice in a simulated environment comprises defining a simulated situation to be influenced by the user including a set of objects that are represented by an attribute-characteristic representation, presenting information concerning a current state of the simulation, obtaining decisions from the user that at least partially determine object designs to be evaluated, evaluating an object design using a value function having multiple optima, updating the simulation with the results from the evaluation, and permitting continued practice by selectively repeating several of these steps. A system executes simulation software that simulates such a situation on a processor, and includes evaluation software for selecting and evaluating design objects by applying a value function having multiple optima. At least one terminal and communication links are provided for information transfer and implementation of the simulated situation. Diagnosis of the user's cognitive approach is also disclosed.