I have to go with RPCookin on this one.
Grew up with gas ovens, but for at least 25 years of my adult life have cooked with electricity.
Have found the electric ovens to be capricious beasts.
Just married and no money, we moved into one apartment that had an electric oven. Went to roast a turkey, probably ten or twelve pounds (good cheap eats). As I recall I set the oven at 350 or so, my usual fall back temp.
Peeked at it in an hour and realized it was done.
Nah, couldn't be. Called the hubby and he said "Nah, couldn't be".
But then we looked again, and cooked it was.
Learned the stove had two settings, full on or off.
The thermostat did not work at all.
Whatever one set the beast for, it cooked at 500 degrees (bought an oven thermometer).
The turkey, however, was surprisingly moist and tasty.
would not fix the darn thing and we lived with that beast for one year.
Learned quite a bit about roasting though.
But my point, oh yeah, I suppose I should get there, is that we have never had an electric oven that actually cooked at the temperature it was supposedly set at.
Since the 'how to cook a turkey in a 500 degree oven incident' have always relied upon an oven thermometer.
They are readily available and cheap.
Now have a fairly reliable gas stove.
Maybe one of these days will stumble upon a turkey at a good price and try to recall what cooking at 500 degrees is all about.