In Product Experience or Expert Experience?, patents expert witness James G. Rice writes:
Quite often when I receive an inquiry from an attorney about a new case, the case deals with a product or device that involves a very specialized and narrow area of design and engineering. A typical example of such a device would be a vacuum cleaner. The attorney will state that they are looking for an expert who has specifically worked in this specific segment of industry in the design and engineering of vacuum cleaners. They often will then state that they are having a hard time locating such an expert. The problem of course is that in such a very specialized area, such individuals are not widely available and are also highly unlikely to be working in litigation support. Even further, should the attorney be fortunate enough to find such an individual, it is frequently the case that they are not be willing to participate in litigation support.