--- /dev/null
+# Testing
+
+
+
+# What is testing?
+
+Software testing is a process by which one or more expected behaviors
+and results from a piece of software are exercised and confirmed. Well
+chosen tests will confirm expected code behavior for the extreme
+boundaries of the input domains, output ranges, parametric combinations,
+and other behavioral **edge cases**.
+
+# Why test software?
+
+Unless you write flawless, bug-free, perfectly accurate, fully precise,
+and predictable code **every time**, you must test your code in order to
+trust it enough to answer in the affirmative to at least a few of the
+following questions:
+
+- Does your code work?
+- **Always?**
+- Does it do what you think it does? ([Patriot Missile Failure][patriot])
+- Does it continue to work after changes are made?
+- Does it continue to work after system configurations or libraries
+ are upgraded?
+- Does it respond properly for a full range of input parameters?
+- What's the limit on that input parameter?
+- What about **edge or corner cases**?
+- How will it affect your [publications][]?
+
+## Verification
+
+*Verification* is the process of asking, "Have we built the software
+correctly?" That is, is the code bug free, precise, accurate, and
+repeatable?
+
+## Validation
+
+*Validation* is the process of asking, "Have we built the right
+software?" That is, is the code designed in such a way as to produce the
+answers we are interested in, data we want, etc.
+
+## Uncertainty Quantification
+
+*Uncertainty quantification* is the process of asking, "Given that our
+algorithm may not be deterministic, was our execution within acceptable
+error bounds?" This is particularly important for anything which uses
+random numbers, eg Monte Carlo methods.
+
+
+[patriot]: http://www.ima.umn.edu/~arnold/disasters/patriot.html
+[publications]: http://www.nature.com/news/2010/101013/full/467775a.html
projects / swc-testing-nose.git / blobdiff