The Pareto Principal
80% of Effects come from 20% of Causes (*80%-20%)
A priority index by Vilfredo Pareto of Italy in 1896.

The Bell Curve
An index showing gradation averages in centre and extremes at either end by Richard Herrstein and Charles Murray of USA in 1994.

Gaussian Distribution
By Carl Friedrich Gauss of Germany in 1809.

Giny Coefficient (Ratio)
Observations of clusters around the mean by Corrado Gini of Italy in 1912.

The 1% Rule n
Only 1% of users of a website actively create new content whilst 99% only view by P. Tomi Austin of…….. 1990.

Parkinson’s Law.
Work expands to fill time available for its completion by Cyril Northcote Parkinson of UK in 1955.

Price’s Law
An unequal distribution of Productivity in most domains of creativity by Derek John de Solla Price of UK in 1963.

Failure Analysis
Failure analysis of 1950’s US Engineering by H. A. Watson in 1960

Fault Tree Analysis Top Down
Analysis of Deductive Faults based on Boolean Logic

Profit Risk
See Pareto Principle

Principle of Least Effort
An information seeking client will tend to use the most convenient search method in the least exacting mode available and stop as soon as minimally acceptable results are found. By Guillaume Ferrero.

Zipf’s Law
The frequency of any word used in talking is inversely proportional to its ranking in a frequency Table. The same relationship occurs in many other Rankings unrelated to language. By George Kinsley Zipf of USA.

Sturgeon’s Law
90% of everything is ‘crap.’ By Theodore Sturgeon of USA

Fibronacci’s Sequence
Every Number after the first two Numbers is the sum of the preceding numbers in Nature and Mathematical Systems. By Leonardo Fibronacci of Pisa, Italy in 1202.

to be continued