Impact must be defined before it can be assessed. Part of the definition is that impact is the consequences of funded vocational education research and development projects and programs, not just the fact of the dissemination of the products of the projects. Programs are defined as a group of funded research and development improvement projects that are seen as having related goals. Impact can be both short term and long term. Short term impact is the consequence(s) of a program improvement project and can be asssessed at the end of the funded life of a project. Long term impact is the consequence(s) of the research and development programs resulting from contributions of several related improvement projects, and is assessed 12 months or more after the funding of three or more of the projects has ceased. Within both short term and long term impact, there are several different types of impact, e.g., intended or unintended, direct or indirect, and positive or negative. The flexible impact assessment system of the Research and Development Section in Illinois begins at the planning stage. The program goals, identified by the Research and Development staff, provide a framework for identifying long term impact. The objectives for meeting program goals become project goals which serve as a basis for identifying short term impact. Project staff participate in impact assessment from project writing through the life of the project. This impact assessment system uses a naturalistic inquiry approach. Data are collected from project staff at the end of projects; in-depth assessment of seven to ten projects is performed; and long term impact is assessed by program area. The information developed is used for further research and project funding considerations. (KC)