The use of expert testimony at trial is expanding. In one study of California trials, Rand Corp. researchers found that experts appeared in 86 percent of the trials, and that on average, there were 3.3 experts per trial. Gross, Expert Evidence, 1991 Wis. L. Rev. 1113, 1119.

However, such testimony can be expensive. A 15-second, computer-generated animation may cost $20,000 and, likewise, DNA testimony can be quite costly. Some litigants simply cannot afford such evidence. Thus, the increased use of expert evidence can place poorer litigants at a distinct disadvantage. That imbalance of resources is especially problematic in an adversary system of litigation.