In science, we make our living as it were by measuring. As a human activity, measurement involves
some errors. When a making measurements, there are (usually) three potential sources of error:
- The person who is making the measurement could make a mistake. The same person who measures the same thing more than once is likely to record different measurements for each trial. Likewise if different people measure the same thing, they are likely to record different measurements.
- The object being measured may change between measurements or a slightly different dimension may be measured at different times.
- The measuring tool may not be completely reliable.