Futures practitioners use a wide range of models and methods (theory and practice), many of which come from other
academic disciplines, including economics, sociology, geography, history, engineering, mathematics, psychology,
technology, tourism, physics, biology, astronomy, and aspects of theology (specifically, the range of future beliefs).
One of the fundamental assumptions in futures studies is that the future is plural not singular, that is, that it consists
of alternative futures of varying likelihood but that it is impossible in principle to say with certainty which one will
occur. The primary effort in Futures studies, therefore, is to identify and describe alternative futures. This effort
includes collecting quantitative and qualitative data about the possibility, probability, and desirability of change. The
plurality of the term "futures" in futures studies denotes the rich variety of alternative futures, including the subset of
preferable futures (normative futures), that can be studied.
Practitioners of the discipline previously concentrated on extrapolating present technological, economic or social
trends, or on attempting to predict future trends, but more recently they have started to examine social systems and
uncertainties and to build scenarios, question the worldviews behind such scenarios via the causal layered analysis
method (and others), create preferred visions of the future, and use backcasting to derive alternative implementation
strategies. Apart from extrapolation and scenarios, many dozens of methods and techniques are used in futures
research (see below)