Test events for the London Olympics have led organisers to revise some of their plans, including moving mounds of earth to reconfigure the BMX track, after unexpected problems came to light.
Speaking ahead of a Diving World Cup event at the new Aquatics Centre, London 2012's director of sport Debbie Jevans told Reuters that the 30 test events so far had provided invaluable feedback for the Games starting on July 27.
The reason that we run these events is to make sure that we get it right at Games time, she explained as athletes tested the springboards and platforms in the sweeping Zaha Hadid-designed building.
The feedback we had from the athletes (about the BMX track) was that, with the headwinds, certainly for the women the first jump was too tough.
We did have a number of athletes fall during the test event. So what we've done is we have reconfigured that track, we've reconfigured the first jump and made it slightly shorter and we've taken away one of the jumps on the first bend and the box jump, she said.
So that was an incredibly important event for us and that work is going on now.
Britain's Shanaze Reade, who won that women's test event at the Olympic Park last August, said afterwards that the track was on the limit when the wind picked up.
The spectators queuing up to get through the airport-style security before streaming through the park to the Velodrome for a cycling World Cup event that started on Thursday will also provide useful information.
The Olympic Park itself remains a building site, with workers in fluorescent jackets dotted around the facility and 270 temporary buildings still to be erected.
That means the spectator access for the test events is different to how it will be at Games time but lessons are being learned inside the venues with the flow of people and seating configurations.
In the indoor events that we've had, they (the venues) were built for what they are going to be in legacy, said Jevans. So we hadn't got the PA systems that we need.
We did have some feedback from spectators that they couldn't understand what our announcers were saying. So we upgraded the PA systems across all of our venues.
At the temporary basketball arena, everything looked great on paper but that test event immediately threw up problems behind the scenes.
When we had the athletes walking into the arena it wasn't the right route. They had to get through the media to get to the field of play. So things like that we have reconfigured which are important to us and we have done that, said Jevans.
After each event we have a full debrief with the team, with the athletes and then we act on that feedback.
(Editing by Clare Fallon)