Hypocrites get offended by the truth.

― Jess C. Scott


sankaran_fig1_360The overall quality of computational modeling depends on a lot of things and one very big one isn’t generally acknowledged, whoever is using the code. How much does it matter? A lot, much more than almost anyone would admit and the effect becomes greater as problem complexity grows.


The most important property of a program is whether it accomplishes the intention of its user.

― C.A.R. Hoare


The computer, the code, the computational resolution (i.e., mesh), the data, the models, and the theory all get acute and continuous attention from verification and validation. When the human element in quality is raised as an issue, people become immensely defensive. At the same time it is generally acknowledged by knowledgeable people that the impact of the user of the code (or modeler) is huge. In many cases it may be the single greatest source of uncertainty.


We don’t see things as they are, we see them as we are.

― Anaïs Nin


UnknownThis isn’t a matter of simple mistakes made in the modeling process; this is associated with reasonable choices made in representing complex problems. Different modelers make different decisions about dealing with circumstances and representing all the “gray” area. In many cases these choices live in the space where variability in results should be. For example the boundary or initial conditions are common sources of the changes. Reality is rarely fully reproducible and details that are generally fuzzy result are subtle changes in outcomes. In this space, the user of a code can different, but equally reasonable choices about how to model a problem. These can result in very large changes in results.


Despite this the whole area of uncertainty quantification of this effect is largely missing. This is because it is such an uncomfortable source of variation in results. Only a few areas readily acknowledge or account for this such as nuclear reactor safety work, the Sandia “Fracture Challenge” and a handful of other isolated cases. It is something that needs much greater attention, but only if we are courageous enough to attack the problem.


It’s funny how humans can wrap their mind around things and fit them into their version of reality.

― Rick Riordan


images-1The capacity to acknowledge this effect and measure it is largely resisted by the community. We are supposed to live in an age where everything is automatic and the computer will magically unveil the truths of the universe to us. This is magical thinking, but the commonly accepted dogma of modernity. Instead the core of value is fundamentally connected to the human element, and this truth seems to beyond our ability to admit.


We do not need magic to transform our world. We carry all of the power we need inside ourselves already.

― J.K. Rowling