The Office of Environmental Engineering and Technology (OEET) briefed the Committee on its draft radon mitigation test matrix, which is described as the conceptual framework for a project design within a research plan still under development. The OEET asked the Committee to address the following question: 'Does the basic approach for the development of the matrix appear reasonable'. The Committee reviewed the document and made the following conclusions and recommendations: (1) the general approach is reasonable; (2) the number of cells in the matrix should be reduced by combining techniques which have similar effects; (3) increased attention should be given to pre- and post-mitigation measurements; and (4) there is a need for greater emphasis on mitigation for new construction.