The document explains the concepts of accuracy and precision in measurement, defining accuracy as the closeness of a measurement to a known value and precision as the reproducibility of measurements. It emphasizes that while measurements can be precise without being accurate, those that are both accurate and precise provide reliable results. An analogy of a dartboard illustrates the distinction between these two terms effectively.

3. Accuracy and Precision -
The Art of Measurement

4. This uncertainty is referred to as an error. Accuracy and
precision are two important factors to consider while
taking measurements. Both these terms reflect how
close a measurement is to a known or accepted value.
Measurement is essential for us to understand the
external world, and through millions of years of life,
we have developed a sense of measurement.
Measurements require tools that provide scientists
with a quantity. The problem here is that the result of
every measurement by any measuring instrument
contains some uncertainty.
Accuracy and Precision

5. Accuracy
Accuracy is defined as ‘the degree to which the result of
a measurement conforms to the correct value or a
standard’ and essentially refers to how close a
measurement is to its agreed value.
Precision
Precision is defined as ‘the quality of being exact’ and
refers to how close two or more measurements are to
each other, regardless of whether those measurements
are accurate or not. It is possible for precision
measurements to not be accurate.

6. What is the difference between Accuracy and
Precision?
Both accuracy and precision reflect how close a
measurement is to an actual value, but they are not the
same. Accuracy reflects how close a measurement is to a
known or accepted value, while precision reflects how
reproducible measurements are, even if they are far from
the accepted value. Measurements that are both precise
and accurate are repeatable and very close to true values.

7. Example of the difference
between Accuracy and
Precision…
The example of a darts board is often used when talking about the difference
between accuracy and precision.
Accurately hitting the target means you are close to the centre of the target,
even if all the marks are on different sides of the centre. Precisely hitting a target
means all the hits are closely spaced, even if they are very far from the centre of
the target.

8. Difference between Accuracy and Precision