The National Acid Precipitation Program (NAPAP) Integrated Assessment discussion of visibility, and its more detailed supporting document, State-of-Science/Technology (SOS/T) Report 24, have been reviewed with regard to completeness in their discussion of visibility measurement methods, chemical analysis procedures to determine the species responsible for visibility impairment and methods to calculate light extinction b(sub ext) budgets. The supporting document, SOS/T Report 24, contains citations and substantial discussion and interpretation of past and ongoing research and monitoring associated with visibility. While both documents are a masterpiece in terms of compiling abbreviated discussions, some aspects of the documents reflect the biases of the authors, as evidenced by omissions of discussions related to visibility studies performed by the U.S. Environmental Protection Agency at Research Triangle Park, NC. The work by the EPA group is of substantial significance in that important complex problems associated with uncertainties in b(sub ext) budgets were addressed and methodology developed to minimize or estimate the uncertainties. The b(sub ext) budget protocols developed by the EPA group should be incorporated into the modeling and methods interpretation sections. More emphasis should be given to the status of measurement technologies which support visibility assessments. In particular, the shortcomings of elemental carbon measurements need to be emphasized.