Statistical rigor and practical utility in thematic map accuracy assessment

Although statistical rigor and practical utility have been advocated as des irable features of map accuracy assessment protocols, specific criteria def ining these features hare not been elucidated. Two criteria are proposed fo r statistical rigor: probability sampling and consistent estimation. Practi cal utility is synonymous with cost, and because cost is directly related t o qualify: decisions regarding practical utility may be evaluated in terms of their effect on quality Four criteria are proposed to define quality of the precision of the accuracy estimates, the population to which sampling i nference is justified, tile assumptions needed to justify inference, and th e accuracy of tile reference data, The first step in planning a statistical ly rigorous, practical accuracy assessment is to construct an efficient, pr obability-sampling-based strategy permitting inference to the full map popu lation. modifications of this strategy to enhance practical utility (i.e., reduce cost of the assessment) should be evaluated using the criteria defin ed for quality and statistical rigor.