Models Methods Software

Dan Hughes

New V&V Book by Pat Roache

I received the following e-mail from Pat Roache regarding his new book about Verification and Validation. He has also made arrangements for reduced prices on two others of his books.

I am pleased to announce the publication of
“Fundamentals of Verification and Validation” by Patrick J. Roache.
Copyright 2009, ISBN 978-0-93478-12-7. 476 pages, subject index.

The book is the successor to my 1998 book “Verification and Validation in Computational Science and Engineering.” About 1/3 of the material is new, including a new Chapter 11 describing the Total Validation Uncertainty approach of ASME ANSI Standard V&V 20 (2009).

The attached file outlines the new features of the book. A complete Table of Contents, including designators for new and modified Sections, will be found on the website.

The price is the same as the 1998 book, U.S. $85.00 (but shipping charges have increased). The book is available directly from our fulfillment house, BookMasters, by email order to

or from at the following.

The orders to BookMasters tend to ship faster since they do not run out of stock. Also, wholesale orders can be placed by contacting BookMasters at

I would appreciate it if you would forward this email to any of your colleagues who might be interested.

Thanks for your consideration.

Patrick Roache

If anyone is interested, the 1998 V&V book is on clearance sale for 1/2 price at US $42.50. Available from or from Amazon at

Likewise, the book “Fundamentals of Computational Fluid Dynamics” is on clearance sale for 1/2 price at US $37.50. Available from or from Amazon at

September 24, 2009 Posted by | Calculation Verification, Verification | , , , , , | Leave a comment

V&V and NNSA Advanced Strategic Computing at LANL

[Updated September 26]
I think the name of the program originally known as the Advanced Strategic Computing Initiative ( ASCI ) is now known as Advanced Simulation & Computing ( ASC ).

[Updated August 26]

I have uploaded an excellent summary, developed by Los Alamos, of the ASC V&V Program at LANL. It is here.

A couple of quotes.

Confidence in simulation extrapolation comes via confidence in physics & numerics models, not calibration to experimental data.

Having “good agreement” between calculations and observations is not sufficient to establish scientifically credible predictive capability.

More and more it seems that the Climate Change Community remains the only holdout among all compute-intensive enterprises relative to application of rigorous, independent V&V to computer software.

Continue reading

August 25, 2009 Posted by | Calculation Verification, MMS, Verification | , , , , , , | 5 Comments

Averaging Planet Earths or Averaging Planet Xs

Update January 23, 2011. I fixed the broken links.

There are several discussions floating around on the subject of comparing GCM-calculated numbers with experimental data. Climate Audit and Lucia both have several threads. There are too many threads to give links; let me know if you need a specific thread. One focus of these discussions is the ensemble-average approach that is considered to be necessary for the comparisons. The ensemble is made up of the results from the various different versions of GCMs that calculate the results. Not only are GCMs different from each other, but the suggested approach is to make perturbations in the initial conditions between the runs.

I have mentioned that the results do not reflect the effects of perturbations in only the initial conditions. Everything about the approach is different between the runs. The GCMs are based on different continuous-equation models, numerical solution methods, application procedures, run-time options, and users, and maybe other aspects. How can we be sure that the results are all appropriate for Earth?

Continue reading

November 4, 2008 Posted by | Chaos and Lorenz | , , , | 3 Comments

Editorial Policies of Scientific Journals

The recent results of an Independent Verification of a calculation at Climate Audit and discussed here brings me to mention the editorial policies of scientific journals relative to Verification, Validation, Software Quality Assurance, and Qualfications of models, methods, software, calculations, users, and applications. I have posted comments about the issues relative to publication of peer-reviewed papers on several blogs and given more detailed discussion here.

According to the results of a very unscientific survey by me, the scientific journals have no interest in these very important issues. Many engineering journals, however, have addressed the problems and developed editorial appropriate policies which must be met by authors.

A little over two years ago I wrote letters to the editors of several scientific journals in which the climate change community publishes papers. I have uploaded an example of the letter.

I think it’s time to followup on that letter, for a second time. Continue reading

August 9, 2007 Posted by | Verification | , , , , , | Leave a comment

A Start on a V&V and SQA Bibliography

Here is a start on a bibliography for V&V and SQA books and articles.
Continue reading

February 23, 2007 Posted by | Calculation Verification, Verification | , , , , , , | 5 Comments