Transcript Accuracy and percision

Data Analysis (Evaluation)

Accuracy vs Precision
• Accuracy – how close a value is to the
“true” value
• Precision – how close values are to each
other
Low Acc
Low Acc
High Acc High Acc
Low Prec High Prec High Prec Low Prec

Percent Error
• Quantitative measurement of accuracy
Absolute Value
(no negative numbers)
Lab Value
| Theoretica l Value - Actual Value |
Percent Error 
100%
Theoretica l Value
Book Value or
Calculated Value