Individualized feedback is an important factor in fostering learning. However, it is often not seen in schools because providing it places considerable additional workload on teachers. One way to solve this problem is to employ critiquing systems. These systems, however, require significant development effort before they can be put into use. In this paper, we describe an incremental authoring model that facilitates the development of educational critiquing systems by integrating manual critiquing with critique authoring. As a result of the integration, the development of critiquing systems becomes an evolutionary process. The model explores a vision for developing educational critiquing systems with much less upfront development effort. We describe a system that we built, the Java Critiquer, as an exemplar of our model. Evaluation results from performance testing and real-life usage of the system have shown that the system successfully provides a tool for accumulating critiques and at the same time supporting teachers critiquing student code. (Contains 16 figures.)