Module 2 Flashcards
What is precision?
Reproducibility or closeness of repeated results to another
When is error reduced?
When you have both good accuracy and precision
What is Guassian distribution?
Symmetrical distribution of data values around a central point
Normal distribution
Same value for mean, median and mode
What does performance outside the expected amount of variation indicate?
Issue with the method
What do statistical QC practices involve?
Running control materials with know. Performance expectations
Data is assessed for measures of central tendency and variation
What are the measures of central tendency? What do they relate to?
Mean, median, mode
Accuracy
What values give what kind of skew?
Mean>median and mode- positive
Mean
What are the measures of variation? What are they related to?
Range, standard deviation and coefficient of variation
Precision
When is precision better?
Low standard deviation and coefficient of variation
What does standard deviation describe?
The spread of values about the mean in a normal distribution
What units is standard deviation given in?
Same at data
Why is using the coefficient of variation valuable?
Because it’s expressed as a percent it can be used to compare the precision of different methods
What is accuracy?
Nearness to true value
