I found this info on a driving website:
We already know of candidates who have failed the hazard test because they have just clicking once on each hazard. It would appear you have a better chance of passing if the mouse is clicked a few times when you see a developing hazard. BUT STOP CLICKING when the hazard has passed. ( you only lose points responding outside the window)
You do need to be careful though. Because if you make lots of unnecessary responses in a very short space of time, or throughout the clip, you will score 0 for that clip...
test is a week from tomorrow..fingers crossed...