The researchers found a high level of recall errors.

ECONOMIST: The Interphone study: Mobile madness | The

This could be due to reporting errors at the local level or not enough sales from the previous year to develop a reliable figure.

FORBES: 10.06.08, 6:00 PM ET

"She cleaned up her game a little bit and didn't make so many unforced errors, and my level dropped off a little bit as well, " said Davenport.

BBC: Venus outclasses Davenport

They continued to heap pressure on Saints, forcing them into a number of errors, before eventually drawing level on 24 minutes.

BBC: SPORT | Rugby League | St Helens 16-24 Leeds Rhinos

At the same time, by removing human employees from the low-level work that most often leads to errors, companies can develop an employee base focused more on the proactive aspects of business that require human creativity and intellect.

FORBES: Outage Prevention: Taking Humans Out Of The IT Equation

Some uncharacteristic errors from Nadal allowed Djokovic to level in game four, but the Spaniard regained the break immediately in an epic fifth game that saw five break points slip by before he cracked a huge forehand winner on the sixth.

BBC: Rafael Nadal wins US Open to seal career Grand Slam

Clijsters did not drop a single game in the first set but her level dropped significantly early in the second, with the number of unforced errors reaching double figures.

BBC: Venus Williams & Kim Clijsters into US Open round two

But with the 28-year-old Spaniard breaking to lead 5-3 in the second set, Federer looked stunned and as his uncharacteristic errors showed no sign of stopping, the match was soon level at one set all.

BBC: Roger Federer & Novak Djokovic progress at Aussie Open