8.2.1. Definition of Precision

Try these first

1. 1.

   Define precision in your own words.

   Hint

   Think about how often the same result is obtained when measuring.

2. 2.

   What is accuracy?

   Hint

   Consider how we determine if a value is true.

3. 3.

   What does precision refer to in measurements?

   • Consistency of results
   • Closeness to true value
   • Size of sample

   Hint

   Remember how often results appear the same.

4. 4.

   True or False: A high precision measurement means it is necessarily accurate.

   • True
   • False

   Hint

   Consider the concept of hitting a target.

5. 5.

   Given that a scale can measure down to 0.01 grams and your sample concentration is 0.05 grams in a total sample volume of 5L, how would you prepare it to get measurable results? Discuss your approach.

   Hint

   Consider the relationship between volume and concentration.

6. 6.

   If you are repeatedly measuring a solution that is known to have an analyte, but the readings are fluctuating widely. How would you determine if this is due to instrument error or the nature of the sample?

   Hint

   Think about the importance of controls and standards in experiments.