**
Accuracy
** -
The extent to which an experimental result agrees with a known or correct value.

**
British System
** -
A system of units, rather arbitrarily based. It is the system of units
primarily used by the United States. It is *not* the system of
units used in science (see metric system). Conversion tables
reside in the "Reference" pull-down menu at the top of most SparkNotes
pages.

**
Metric system
** -
A standardized system of units based on 10. Generally, the measurement system
used in science, and in everyday life through most of the world (but not in the
United States, which uses the British system). Conversion tables
reside in the "Reference" pull-down menu at the top of most SparkNotes
pages.

**
Precision
** -
The extent to which an experiment is reproducible.

**
Scientific Notation
** -
A system of representing large numbers, following the model *ax*10^{b}, where
"a" is the value and "b" is number of places the decimal place had to move in
order to express a in manageable terms. 1123,000,000 is represented in
scientific notation as 1.123*X*10^{9}.

**
Significant Figures
** -
Digits in a recorded value that are reliable and believable.

**
Units
** -
A uniform standard of measurement.