Most prosecution marijuana experts have never faced a real voir dire and do not fare well when they are tested, and asking the right questions can expose an alleged expert's lack of knowledge. The voir dire can concentrate on other areas as well, depending on the crux of the case, and can test each aspect of an expert's abilities. Direct examination can be used to present new theories to the court and to rebut expert testimony. For instance, in marijuana cultivation cases, the question of personal use or intent to distribute is an important issue. The prosecution can make a conclusion based on such criteria as the quantity of marijuana, the number of plants, the presence of scales, packaging material, large amounts of cash, indications of wealth, and the sophistication of the garden. Defense experts can bring other issues to the court's attention, including the size of the garden, actual and expected yields, different plant varieties, how much the defendant used, and different grades of marijuana and their value and use.