The portion of risk that cannot be measured or quantified. FX SignificanceWhen...

All event s, both positive and negative whose probabilities are neither 0% nor 100%. Uncertainty is a distinct characteristic of the project environment. [D02229] RMW Lack of knowledge of future event s. See also Project Risk. [D02094] PMK87 The possibility that event s may occur which will impact the project either favorably or unfavorably. Uncertainty gives rise to both opportunity and risk. See also ( project) risk. & [D02095] FWH RMH A condition, event, outcome, or circumstance for which the extent, value, or consequence is not predictable. [D03704] DSMC source of risk derived from a lack of sufficient knowledge about the underlying probabilities of adverse event s and/or their consequences. [D05138] RAMP

Unmeasurable risk.

The lack of precise knowledge based on the amount and quality of evidence or data available.

The limit on the precision of a measurement. Analytical balances, for example, can weigh an object with an uncertainty of ñ0.001 or ñ0.0001 grams.

Uncertainty results from a lack of perfect knowledge of many factors that affect stock assessments, estimation of reference points, and management. Rosenberg and Restrepo (1994) identify 5 types: measurement error (in observed quantities), process error (or natural population variability), model error (mis-specification of assumed values or model structure), estimation error (in population parameters or reference points, due to any of the preceding types of errors), and implementation error (or the inability to achieve targets exactly for whatever reason).

In a nuclear decay measurement, uncertainty refers to the lack of complete knowledge of a sample's decay rate due to the random nature of the decay process and the finite length of time used to count the sample.

parameter associated with the results of a measurement, that characterizes the dispersion of the values that could reasonably be attributed to the measurand.

That which is uncertain; something unknown.

Conditions where there is no reliable data to help predict future events.

When a possible occurrence is so unpredictable that its outcome is pure chance.

as used by economists, the situation where not only is the exact outcome unknown, but the range of outcomes and/or their probabilities of occurring are also unknown

Principle - Heisenberg physics' theory which states "The more precisely the position [of a subatomic particle] is determined, the less precisely the momentum is known in this instant, and vice versa." Fundamentally this places a limit on knowability.

See Uncertainty Principle

It is impossible to know exactly where something is and where it is going. This is a fundamental law of nature has a major effect on quantum theory.