Many of the arguments against GIS certification are based on the fact that GIS embraces so many different professions that it is difficult to get anybody to agree what GIS is and what it is not. Opponents of GIS certification argue that GIS is too broad for a common set of competency standards or that more time is needed for the field to evolve. Others note that certification will increase the cost of hiring GIS professionals and that professional organizations may initiate certification as a means of generating income. Others explain that not all GIS activities affect public welfare and safety and thus do not require oversight and are against the increased bureaucracy that is necessary for any certification or licensing program. Others base their arguments on historical pattern of GIS use by land managers and others that has been successful without certification.