Outliers, Box Plots Flashcards
1
Q
What are outliers?
A
Extreme values relative to the bulk of values in a data set
2
Q
What causes outliers?
A
Inaccuracies in data processing
Problems with methodology
Actual extreme value from an unusual participant
3
Q
How is an outlier detected based on the Z-Score?
A
If it is more than 3 or less than -3
When the distance from the mean is more than 3 times of SD
4
Q
How is an outlier detected based on the Inter-Quartile Range? (1st and 3rd Quartile width)
A
If the range value is greater than 1.5 above the 3rd Quartile or smaller than 1.5 below the 2nd Quartile
5
Q
What is a box plot?
A
Summarises quartile-based statistics of a data set
6
Q
What does a box-plot include?
A
Location of quartiles
Range of data excluding outliers
Outliers detected by quartile
