This overall score is made up of hard floor dirt pick-up (40%), dirt removal from carpet (30%), cleaning corners and edges (15%), pet hair removal (15%). Ease of use is not scored as all models were very easy to operate.
For carpet we sprinkle sand evenly into a section of carpet and let the robot run for a set period of time on the carpeted area. The sand collected is weighed and recorded. With normal vacuums we pre-load the dust collector with dust, but robot vacs have a very small dirt receptacle which is normally emptied after a cleaning session, so we don't pre-load them.
We embed cat hair into the carpet and, as with the dirt pick-up test, we allow the robot vacuum cleaner to run for 15 minutes. We rate the vacs based on how much cat hair is left behind after the test.
Noise is measured at two metres. Even though most models produce similar sound readings, some emit a high-pitched whistle or various tones and alerts (even music!) that some people may find irritating.
We use the information received from members who took part in the 2015 reliability survey to rate the most popular brands for reliability. na means no/not enough responses were received for this brand.
Used to create an invisible barrier, for blocking off open doorways or other areas you don't want the robot to enter. Some come in the form of infrared towers, but increasingly the barriers are defined using apps on your smart device.