Correlation, in basic terms, is trying to match the data that you measure off the car against your simulator data.

If they do match, then you know that your development, or simulation environment, is good, and you can use that to develop the car. Everything correlates well and you know that you can trust your simulation environment, which is much cheaper and much more efficient in terms of developing a car. You know that something that has given you a gain in your simulation and development environment is going to give you a gain on the real car.

SMEDLEY: What teams do on the first day of F1 Pre-Season Testing

Where teams have problems is when their development or simulation environment – so CFD [Computational Fluid Dynamics] or wind tunnel – doesn’t describe well what happens in reality (although in truth, no-one’s wind tunnel correlates absolutely 100%). At that point, you’ve got a problem and you’ve got to try and understand where the mismatch is coming from.