this is the Technology Report.Goal line technology made its debutin international footballat the Confederations Cup in Brazilthat ended on sunday.The move to goal line technologyfollows international pressureon the sport's governing body FIFAafter a missed call in the 2010 World Cup.Video replays of a match clearly showthat England's Frank Lampard had scored a goal against Germany.However, that goal was denied because neither the refereenor linesman saw the ball cross the goal line.The incident caused such a stir that FIFAapprove the development of goal line technology.That technology was put to the testat the Confederations Cup in Brazil which began June 15.Bjorn Linder is the chairman of GoalControl,the German-based companythat won the goal line technology contractfor this year's Confederations Cup.His team spend weeks in Brazil before the gamesas part of the FIFA certification process."The whole system uses 14 camerasthat are installed on the catwalk.We have seven cameras per goal and computersthat are connected to those cameras.The computers are catching the images,around 500 pictures per second."Computers track the path of the ball in real timeand reconstruct the play."Once the computer perceives the ball has crossed the goal line,it gives a signal to the referee's watch,so all the referees on the field receive the signal.It vibrates and gives an optical signal 'goal'and he knows a goal has occurred."Electronic eyes on the goal line may settle arguments,but the data is still only a reconstruction of reality.Nic Fleming is a London-based science and technology writer,he believes the use of goal line technology is a chanceto educate people about the role of uncertainty in science."These are fantastic tools,but let's be realistic about their limitations,that science is about probabilities.What better way than to have this message in a game so popular."GoalControl claims an accuracy of plus-or-minus 5 millimeters,this is well under FIFA's minimum requirement of plusor minus 3 centimeters.Nic Fleming would like to see that number flashed on the screen.He says viewers could compare the replaysto the computer reconstruction and learn a little science."The wider point really is that science is centralto many public debates today,whether that's climate change or nuclear power or genetic modification.In all of these cases science provides probabilities.It does not provide yes-no, black-white answers that is quite important to the public understands that."Goal-line technology may become a central part of the sport,but it is important to remember that is still the referee,not the computer, that makes the final call.And that's the Technology Report from VOA Learning English,for more about reports, visit our website at 51voa.com.