Experts have tested various types of vacuums, including shop vacuums, canister vacuums, robot vacuums, and pool vacuums, to determine the best ones. The tests appear to have focused on the vacuums' ability to handle specific tasks, such as cleaning up pet hair or working in garages and pools. The results of these tests have been compiled into lists of top-rated vacuums, although it is unclear if the lists are comprehensive or limited to specific types of vacuums.