Abstract:
A surprisingly effective measurement challenge involves simply the reading of three thermometers, one of which is deliberately broken so it gives the temperature of ice water as 38 C (which is precisely what most students record). Years later students report that they have never forgotten their first physics class when they so eagerly insisted that ice-water was much hotter than room-temperature water! They proudly tell how they learned to think when taking readings and no longer unequivocally trust instruments (or physics teachers!).