Novices in programming face many problems affecting their learning process and programming success. Learning to program includes using the programming environment, learning a programming language's syntax and semantics, understanding a problem and translating it into an executable plan, developing algorithms and programs, and testing and debugging programs. The knowledge-based programming environment ELM-PE is designed to support novices learning the programming language LISP. It has several features that are especially useful in problem solving in a new complex domain. These features are designed to avoid unnecessary mistakes, give immediate feedback, reduce memory load, support learner activity, and support example-based learning. Students can work on exercises with and without help from the system, to choose exercises on their own, to plan, program and debug function definitions, and to ask the system for help. The system remains passive as long as possible and offers advanced help only on demand. In an evaluation study, ELM-PE proved to be effective in facilitating learning. It was found that students who used the helping facilities often during the first lessons of programming performed well in a final exam; the more support available during the learning phase, the better students managed to solve the final programming problems when they were unable to use the advanced help system. (Contains 15 references.) (AEF)