The other day I got on a bus at the downtown main bus terminal. Behind me, a woman started to interrogate the driver.
“Do you go to Pohjantie?”
When the bus driver did not respond (likely, he does not remember all the names of the roads on his route), she changed tactics:
“Your sign says Kuokkala. Which route do you take?”
There are three roads to Kuokkala, which is on the other side of Lake Jyväsjärvi: two drive around the like on opposite sides, and one takes a bridge over the lake. One of the drivearounds in fact goes through Pohjantie (as well as a neighbourhood called Tikka), and several buses take that route. Buses also use the bridge; to my knowledge, no bus uses the other driveraound route.
“On the way back I’ll go through Tikka.”
“So you end up at Viherlandia?” Viherlandia is the terminus of one of the bus routes that drives through Pohjantie.
“But Kuokkala, how do you get there?”
“I’ll take the bridge, then drive around the Kuokkala centre and then turn right …”
“… toward Nenäinniemi. You’re not my bus, thanks.”
In fact, she was wrong; it would have been her bus had she waited to hear the bus driver’s reaction to Nenäinniemi; he wasn’t going there, instead, he would have just turned to Tikka and from there through Pohjantie back to downtown.
But I suspect she had a mental model: all buses in Jyväskylä run (so she probably thought) pendulum routes, going back the same route they take. So, once she had established that the bus took the bridge, she had all the information she thought she needed.
In fact, that particular line runs a mixed pendulum and ring model: going Northeast from the downtown terminal, it runs to a particular suburb and retraces its steps back to downtown; however, southbound, it goes over the bridge to Kuokkala and drives a semiring route in Kuokkala, existing through the Pohjantie drivearound and making its way back to the downtown terminal.
People sometimes say that science is objective and empicial, and that the data speak for themselves. This sort of a statement forgets that data mean nothing by themselves, and your conclusions are no better than your model.