Kwalify Users' Guide (for Ruby and Java)

makoto kuwata <kwa(at)>
last update: $Date: 2006-05-14 13:57:07 +0900 (Sun, 14 May 2006) $


Kwalify(*1) is a tiny schema validator for YAML and JSON document.

You know "80-20 rule" known as Pareto Law, don't you? This rule suggests that 20% of the population owns 80% of the wealth. Kwalify is based on a new "50-5 rule" which suggests that 5% of the population owns 50% of the wealth. This rule is more aggressive and cost-effective than Pareto Law. The rule is named as "Levi's Law".

schema technology (A) cover range (B) cost to pay (A)/(B) effectiveness
XML Schema 95% 100% 0.95 (= 95/100)
RelaxNG 80% 20% 4.0 (= 80/20)
Kwalify 50% 5% 10.0 (= 50/5)

Kwalify is small and in fact poorer than RelaxNG or XML Schema. I hope you extend/customize Kwalify for your own way.

Pronounce as 'Qualify'.

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