In the seminar, ongoing research related to error budgets will be presented. Some error budgets will be given for different natural resource monitoring and projection systems. The assumptions of error-free data and models usually do not hold in the real world. Error is a natural property of surveys and models. An error budget can be considered as a catalog of the different error sources in both surveys and models. The error-budget can be used for many purposes such as data correction, model evaluation, quality control, decision-making of management, etc. The benefit of an error-budget model is substantial. First, the error budget can be used to evaluate the statements made from a survey or a model. Given all the errors, the error budget model can tell us if the estimates and projections are valid or invalid. Estimates and projections are valid only if they are within certain error limits. The statements based on estimates and projections usually provide little useful information if its error is out of the given limits. Second, the error-budget can guide in designing surveys and models. With error sensitivity analysis, all types
of error sources can be tested to find their effects to the final statement. We can put our effort toward controlling the error sources that contribute the most to the final error based on the sensitivity of the error sources. In this way we may obtain maximum accuracy with minimum cost. Third, an error-budget provides information for error correction. To correct errors, we have to know the sources of the errors. Errors from different sources may need different procedures for error correction. Using the error decomposition, we can know what are the major cause of the errors. Finally, an error budget can be used as a basis for "virtual experimentation" when using conceptual models for testing different environmental hypotheses and scenarios.