Laws and Rules

Here are some well known laws and rules, that are really useful in my opinion in testing area. Noway they are the only ones or the most important or something like this - they are just some laws that I prefer to remmember about while I am working.



KISS Principle by Kelly Johnson
Keep It Simple, Stupid!

YAGNI Principle
You Ain't Gonna Need It

New Jersey Style by Richard P. Gabriel
Worse Is Better
There is a point where less functionality ("worse") is a preferable option ("better") in terms of practicality and usability.

DRY Principle by Andy Hunt and Dave Thomas
Don't Repeat Yourself

Duck Test
If it looks like a duck, swims like a duck, and quacks like a duck, then it probably is a duck.

I Know It When I See It by Potter Stewart

Murphy's Law by Edward Aloysius Murphy
Anything That Can Go Wrong, Will Go Wrong

Sturgeon's Law by Theodore Sturgeon
Nothing Is Always Absolutely So

Parkinson's Law by Cyril Northcote Parkinson
Work Expands So As To Fill The Time Available For Its Completion.
The amount of time which one has to perform a task is the amount of time it will take to complete the task.

90–9–1 Rule
1% of people create content, 9% edit or modify that content, and 90% view the content without contributing.

Pareto Principle by Vilfredo Pareto
80% of your complaints come from 20% of your customers.
80% of the effects come from 20% of the causes.


And at the end the great words of Joshua Bloch ("Effective Java programming"):

Learning the art of programming, like most other disciplines, consists of first learning the rules and then learning when to break them.