Human Development Index, is a composite development indicator. Composite because it is made up of a number of other indicators.

The components that make up the Human Development Index are:

• A long and healthy life: Life expectancy at birth
• Education index: Mean years of schooling and Expected years of schooling*
• A decent standard of living: GNI per capita (PPP US$)

Countries are given a HDI score which is a number from 0 to 1. They are then grouped by this score into four categories:

• very high human development
• high human development
• medium human development
• low human development

The global pattern of HDI is shown on the map below:

Source of the above image: http://en.wikipedia.org/wiki/File:2011_UN_Human_Development_Report_Quartiles.svg

In 2011 the highest ranking country according to the Human Development Index was Norway (0.943); and the lowest was the Democratic Republic of the Congo (0.286).

More information can be found on the United Nations Human Development Project website: http://www.undp.org/

*This is a change for the 2011 HDI Index, prior to 2011 the Education aspect was measured by the adult literacy rate (with two-thirds weighting) and the combined primary, secondary, and tertiary enrollment ratio (with one-third weighting).