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# Verification, Validation, and Confirmation of Numerical Models in the Earth Sciences

## Details

**Authors** Oreskes, Naomi and Shrader-Frechette, Kristin and Belitz, Kenneth

**Year** 1994

**Publisher** Science, 263(5147), 641–646

**Kind of work** article

**Discipline** Geology

**Secondary disciplines** Philosophy, Hydrology

**Applied** false

[Read it at the publisher](https://doi.org/10.1126/science.263.5147.641) 
10.1126/science.263.5147.641

## In authors' words

### What they set out to do (purpose)

To examine whether numerical models of natural systems can be verified or validated, and what agreement between model and observation establishes.

### How they did it (methods)

Philosophical and logical analysis of modeling practice in the earth sciences.

### What they found (results)

The authors argue that verification and validation of numerical models of natural systems is impossible because such systems are never closed and model results are never unique. Agreement between prediction and observation gives only partial confirmation, since complete confirmation is ruled out by the fallacy of affirming the consequent and by limited access to natural phenomena. Models can be evaluated only in relative terms, and their main value is heuristic.

## Commentary

### In short

An argument that numerical models of natural systems cannot be proven correct, only more or less supported, and that their chief value lies in helping investigators think.

### Response

The paper separates verification, validation and confirmation, which is a distinction doing real work. It turns on the point that natural systems are open and so cannot be fully captured by a bounded model, which is a systems claim, and on the relation between model and observation. The model as one of several non-unique descriptions of the same system is close to a perspectives claim, but the authors do not frame it in terms of vantage point, so it is not ticked. Findings are drawn from the abstract only.

**Patterns it shows** D, S, R

**Added** 2026-10-26

**How to cite this** Oreskes, Naomi and Shrader-Frechette, Kristin and Belitz, Kenneth (1994). Verification, Validation, and Confirmation of Numerical Models in the Earth Sciences. Science, 263(5147), 641–646.