The Importance of Effective Vacuuming

"Based on many tests conducted by independent associations (e.g., CRI) and agencies in recent years, it is unreasonable to suggest that dry soil removal is not an essential procedure to perform before wet cleaning begins.  Dry soil removal is accomplished in one preparatory (required occationally) and three physical removal phases.  First, pile preparation (using grooming tools) to untangle the pile of some high-pile residential carpet may be necessary before dry vacuuming.  With commercial carpet , pile preparation simply is not an issue.  Second, physical soil removal is accomplished in three phases: overall vacuuming with an upright vacuuming entry area hand vacuuming (removal of destructive build-up of abrasive soil), and periodic edge vacuuming to remove fine dust and soils that upright vacuum nozzles are unable to remove."

Jeff Bishop
The Science of Carpet Cleaning, 2003