ASSESS is an interactive program designed to assist the user in statistically determining the quality of data from soil samples taken at a hazardous waste site. The user-friendly program was created to assess precision and bias in the sampling of soils. The total error in a sampling regimen is the sum of measurement variability and natural variability of the contamination. It is the field scientist's challenge to mitigate the measurement variability by careful sample-taking, thoughtful sampling design, and the use of recommended quality assessment samples. The greatest potential for error, both random and bias, is in the sampling step. Field conditions, tool contamination, operator differences, all can affect variability and bias in a sample before it gets to the analytical step. The value of ASSESS is its ability to detect and isolate error at critical steps in the sampling and measurement function. ASSESS plots graphics directly on the screen to give the user a quick look at data or results.