[SystemSafety] A Critical-System Assurance Manifesto

[Derek M Jones]

Peter,

> * Statistical Evaluation
Chapter 1, the Urn model.

The empirical evidence is that the Urn model is not a good
model of faults discovery.

The Urn model gives equal weight to each item it contains.

Some faults are more likely to be discovered than others, while
other faults are very rarely seen.  This is not the Urn model
view of the world.

The Urn model has lots of mathematical history associated with
it and appears in all the probability text books; which makes it
a favorite of professors.

Isn't it about time that people started using a model with a
closer connection with reality?

-- 
Derek M. Jones           Software analysis
tel: +44 (0)1252 520667  blog:shape-of-code.coding-guidelines.com