Practical Stats Courses

Online courses in environmental statistics, at your desk.

1. Nondetects And Data Analysis
Statistical methods for data with nondetects (also called "censored data"). Methods to ompute means, UCL95s, hypothesis tests, regression, trend analysis and multivariate stats (PCA, cluster analysis, etc.), all without substituting one-half the DL for nondetects. A free online course, now available on our NADA course page.

The NADA course ia based on the textbook Helsel, D.R. (2012) Statistics for censored environmental data using Minitab and R (2nd edition), written by the instructor.
The previous edition had the title Nondetects And Data Analysis (2004). The second edition included material on using R statistical software, a chapter on multivariate methods for nondetects, and other additions.

Reviews of the First Edition:
"Sound methods......a practical guide" SETAC Globe, March 2005
"I would recommend this book for anyone conducting or reviewing the analysis and reporting of environmental data..." Technometrics, February 2006
"..clear explanations...good instructions...solid advice...This is the book I will share with consulting clients who have data with below detection limit values." Journal of the American Statistical Association, March 2006
"...a 'must-have' desk reference for environmental practitioners dealing with censored datasets." Vadose Zone Journal, February 2006

Reviews on Amazon:
"This book should be owned, and read, by anyone and everyone who ever has to deal with environmental monitoring data." -- Tim Bray
"Excellent Resource" -- Jill Lundell
"Sensible advice...I recently incorporated many of the concepts from this book into regulatory requirements for coastal water quality standards" -- Steve Saiz
"This book fills a huge gap by providing proper statistical methods from the fields of medical and industrial research to the analysis of censored environmental data. ... I have found the information to be extremely helpful in my work as an in-house environmental consultant working for a large manufacturing company." -- Saul Furstein

2. Applied Environmental Statistics
A survey of environmental statistics, from confidence, prediction and tolerance intervals to regression models and trend tests in many varieties. Parametric, nonparametric and permutation tests.
This course is not available online at the present time. Most of the course material is available in
the 2020 revision of the classic textbook Statistical Methods in Water Resources now available as
* a free download. See the link on our Books page
* an inexpensive hardcopy sold by the US Geological Survey, at

Online at:

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