In 1960, John Adams, the Director General, created three committees to manage experiments for each bubble chamber experimental technique used at CERN. These replaced the previous Advisory and Bubble Chamber committees. At the end of the bubble chamber period, the system was again changed and based on machine, rather than experimental technique. The committees were changed and merged in order to accommodate to this. Since then, the committees have changed based on the creation and decommissioning of facilities and accelerators.