The U.S. Department of Education has not yet published an official guidance document for using NAEP achievement level scores to confirm state testing results. A review of the literature, however, identified four principles that inform the valid use of NAEP scores in a confirming analysis. The principles address the appropriate NAEP statistics to use to confirm state testing results. They articulate the difference between NAEP and state definitions of "proficiency". They also provide a rationale for avoiding point-by-point comparisons, and advocate a rationale for using trend analysis. The principles that are detailed in this article include the following: (1) The percentage at or above "Basic" is the appropriate NAEP statistic for confirming state AYP results; (2) The NAEP definition of"Proficient" is not synonymous with "proficiency" in a subject; (3) Confirmation of state testing results should not be conducted on a point-by-point basis; and (4) Confirmation should not be construed as a strict validation of the state's test results. This article introduced these principles as a result of the Idaho State Superintendent of Public Instruction having forwarded a question from the Chairman of the Idaho Senate Education Committee. The Senator wanted an explanation for the "large discrepancy" in 2005 between the percentages of Idaho students scoring proficient or better in reading as reported by the state assessment and by the National Assessment of Educational Progress (NAEP). His specific reference was to a press release from the Fordham Foundation that labeled Idaho as one of the worst offenders in the "race to the bottom" by lowering standards and making state tests easier (Leischer, 2005). The Senator could well have pointed to other reports from well-known individuals and prominent organizations that also advanced variations of the "large discrepancy theme." Here, author Bert Stoneberg argues that the authors of these reports were either unaware of or elected to ignore published information related to the valid use of NAEP achievement level scores to confirm state test results. Stoneberg explains here that had those authors exercised due caution in their analyses of the 2005 data (i.e., had they paid attention at least to the principles or "ground rules" identified in this paper) their findings undoubtedly would have been different, if not opposite.