[R] Curious about nomenclature: random deviates

Baskin, Robert RBaskin at ahrq.gov
Tue Apr 6 15:26:21 CEST 2004

< Does anyone know why they're called random deviates, as opposed to random
Others will probably give you some technical reason about random numbers can
be considered as random deviates from a mean (I think at least the 1875
Galton paper at http://www.mugu.com/galton/ uses similar terminology (I'm
not claiming this is the earliest use - just the easiest to access at the

But everyone knows the real reason for the term is to create the oxymoron
'normal deviates' - it's a great name for a softball team of statisticians


-----Original Message-----
From: Andrew Robinson [mailto:andrewr at uidaho.edu] 
Sent: Tuesday, April 06, 2004 12:13 AM
To: r-help at stat.math.ethz.ch
Subject: [R] Curious about nomenclature: random deviates

Hi all,

a student of mine recently stumbled whilst reading the R help files for the 
statistical distributions.  She was confused by their assertion that, for 
example, 'rnorm' generates random deviates.  I have seen this label used 
elsewhere, although it does not seem universal - for example, Ripley (1987) 
doesn't have it in the index. Does anyone know why they're called random 
deviates, as opposed to random numbers?

Andrew Robinson                      Ph: 208 885 7115
Department of Forest Resources       Fa: 208 885 6226
University of Idaho                  E : andrewr at uidaho.edu
PO Box 441133                        W : http://www.uidaho.edu/~andrewr
Moscow ID 83843                      Or: http://www.biometrics.uidaho.edu
No statement above necessarily represents my employer's opinion.


Ripley, B.D. 1987. Stochastic Simulation. Wiley-Interscience;

R-help at stat.math.ethz.ch mailing list
PLEASE do read the posting guide!

More information about the R-help mailing list