Environmental exhibits that are clear, accurate, and simple are a prerequisite for explaining the technical elements of an environmental case. Exhibits must also be factually and scientifically correct. Exhibit errors arc unintentional due to transcription or preparation errors or intentional, as identified by a pattern of bias (Tufte, 1983, 1990, 1997). Intentional errors include:

• Exaggerated vertical or horizontal scales • Selective data presentation • Data contouring (manually and computer-generated) • Color-coded data that obscure source areas • Contaminant transport models based on biased data

When trial exhibits are exchanged, a concerted effort is required to validate their accuracy. Obtain the underlying information such as chemical results, especially in an electronic format, early in the discovery stage so that your expert witness and/or confidential consultant can quickly review the underlying data used to produce the trial exhibits. Determining that a trial exhibit is scientifically accurate benefits all parties.