Jennifer Part 1

Jennifer is a researcher, and someone from the traffic department approaches her. A particular junction is found to be hazardous.

She took the job and investigated the junction. She made a count, that cars that turn right have 1% chance of meeting an accident. Going straight is 0.5% and left is 0.2%. So her theory goes that 'right turn causes accident.' True?

Jennifer subsequently measured the hardness and gradient of the right turn. Models of the car that came by. And radius of the turn. Has she come closer to reality?

Soon, people starts to loose interests in the junction, but yet another one caught attention. Now, she being an expert in traffic accident investigation, is tasked to look at that junction too. Is she going to do better because of her experience?

How much are we a researcher like Jennifer? What's wrong with her approach?