Read the passage and answer the question.

A school science club made a rain gauge from a straight-sided plastic bottle. They marked equal intervals on its side and placed it in an open area away from roofs and trees. After each shower, a student recorded the water level and emptied the bottle. One reading was unusually high because the bottle had been left under a dripping roof edge. The club excluded that reading and moved the gauge to a clearer spot. They learned that measuring carefully also means checking where the instrument is placed.

Which inference is most consistent with the passage?