What is The World Factbook's source for a specific subject field?
The Factbook staff uses many different sources to publish what we judge
are the most reliable and consistent data for any particular category.
Space considerations preclude a listing of these various sources.
The names of some geographic features provided in the Factbook differ
from those used in other publications. For example, in Asia the
Factbook has Burma as the country name, but in other publications
Myanmar is used; also, the Factbook uses Sea of Japan whereas other
publications label it East Sea. What is you policy on naming geographic
features?
The Factbook staff follows the guidance of the United States Board on
Geographic Names (BGN). The BGN is the component of the United States
Government that develops policies, principles, and procedures governing
the spelling, use, and application of geographic names--domestic,
foreign, Antarctic, and undersea. Its decisions enable all departments
and agencies of the US Government to have access to uniform names of
geographic features. The position of the BGN is that the names Burma
and Sea of Japan be used in official US Government maps and
publications.
Why is most of the statistical information in the Factbook given in
metric units, rather than the units standard to US measure?
US Federal agencies are required by the Metric Conversion Act of 1975
(Public Law 94-168) and by Executive Order 12770 of July 1991 to use
the International System of Units, commonly referred to as the metric
system or SI. In addition, the metric system is used by over 95 percent
of the world's population.
Why don't you include information on minimum and maximum temperature
extremes?
The Factbook staff judges that this information would only be useful
for some (generally smaller) countries. Larger countries can have large
temperature extremes that do not represent the landmass as a whole. In
the future, such a category may be adopted listing the extremes, but
also adding a normal temperature range found throughout most of a
country's territory.
What information sources are used for the country flags?
Flag designs used in The World Factbook are those recognized by the
protocol office of the US Department of State.
Why do your GDP (Gross Domestic Product) statistics differ from other
sources?
GDP dollar estimates in The World Factbook are derived from purchasing
power parity (PPP) calculations. See the Notes and Definitions section
on GDP methodology for more information.
On the CIA Web site, Chiefs of State is updated weekly, but the last
update for the Factbook was an earlier date. Why the discrepancy?
Although Chiefs of State and The World Factbook both appear on the CIA
Web site, they are produced and updated by separate staffs. Chiefs of
State includes fewer countries but more leaders, and is updated more
frequently than The World Factbook, which has a much larger database,
and includes all countries.
Some percentage distributions do not add to 100. Why not?
Because of rounding, percentage distributions do not always add
precisely to 100%. Rounding of numbers always results in a loss of
precision--i.e., error. This error becomes apparent when percentage data
are totaled, as the following two examples show: