Starting in March of 1999, the Cooperative Program for Operational Meteorology, Education, and Training (COMETâ) has been tasked by the National Weather Service to conduct the Advanced Weather Information Processing System (AWIPS) Validation Effort (AVE). Work to date has encompassed three phases. Phase one was designed to support the commissioning of AWIPS version 4.2 by conducting qualitative assessments of displayed basic model fields such as temperature, winds, and moisture parameters. Phase two began a more quantitative evaluation of AWIPS model derived fields that use techniques such as mathematical differencing or integration, non-standard conversions, and empirically derived formulas. In both phases AWIPS displays of the Eta and AVN model fields have been compared with those from the General Meteorological Package (GEMPAK). All fields available have been thoroughly examined and documented. Documentation includes a basic definition of the field, an example of the AWIPS and GEMPAK displays, as well as the calculations used to derive the field. The third and final phase began in April 2001 and has examined the 'Sounding' view of the AWIPS Volume Browser, which has received the majority of the questions submitted to the AVE team by forecasters in the field. AWIPS is compared to model sounding plots from the NSHARP software. Additional work in phase three is to re-examine those fields from phases one and two that have been corrected in more recent versions of AWIPS. Any discrepancies found have been jointly investigated with the Forecast Systems Laboratory (FSL). Those discrepancies that are deemed significant are submitted to the Systems Engineering Center, Development Branch (formerly AWIPS Program Office) as an official discrepancy report (DR). Documentation and resolution of discrepancies have been posted on-line monthly for forecasters to view. Forecasters can also send discrepancy reports to us via the AVE Web site. Results of investigation in all phases and examples of the documentation will be presented. The AVE Web site can be found at http://meted.comet.ucar.edu/awips/validate/index.html.