Cone of Plausibility
Also known as: Futures Cone, Voros Futures Cone, Cone of Plausible Futures, Plausibility Cone Analysis
The cone of plausibility, often called the futures cone, is a framing device for scenario work that projects a baseline 'expected' future and then bounds a widening cone of alternative futures around it by varying the key drivers and assumptions on which that baseline rests. Drawn from the present at the cone's apex, the trajectory fans out as it extends into the future, because uncertainty compounds over time and the range of futures that remain plausible grows wider the further out one looks. Joseph Voros, building on Charles Taylor's earlier cone imagery, formalized the device by nesting categories of futures — possible, plausible, probable, and preferable — within the cone, giving foresight practitioners a shared vocabulary for distinguishing what could conceivably happen from what could reasonably happen and from what is most likely. As Bishop, Hines, and Collins note in their survey of scenario techniques, the cone provides a disciplined way to generate and bound a manageable set of alternative scenarios.
Key highlights
- Gives a shared, intuitive vocabulary — possible, plausible, probable, preferable — for talking about alternative futures.
- Makes the baseline and its assumptions explicit, then generates alternatives by transparently varying those assumptions.
- Captures how uncertainty widens over time through the cone's expanding geometry, countering single-future planning.
- Bounds scenario work to a manageable, defensible set drawn from the plausible band rather than open-ended speculation.
Intuition
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How it works
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When to use it
Use the cone of plausibility when you need to frame and bound a set of scenarios around a focal question and want a clear, communicable way to distinguish the expected future from credible alternatives. It is well suited to early scenario-building, to strategy stress-testing, and to settings where decision-makers default to planning for a single projected future and need to be shown the wider envelope of plausible outcomes. The device works best over medium-to-long horizons where uncertainty genuinely widens with time and where the relevant drivers and assumptions can be identified. It is less useful when the future is highly constrained and near-term, when rich relational scenario logics (such as full intuitive-logics scenarios) are needed rather than a framing cone, or when the team risks mistaking the neat geometry of the cone for a precise probabilistic forecast. It is commonly paired with environmental scanning to source drivers and with intuitive-logics methods to flesh out the retained scenarios.
Strengths & limitations
- Gives a shared, intuitive vocabulary — possible, plausible, probable, preferable — for talking about alternative futures.
- Makes the baseline and its assumptions explicit, then generates alternatives by transparently varying those assumptions.
- Captures how uncertainty widens over time through the cone's expanding geometry, countering single-future planning.
- Bounds scenario work to a manageable, defensible set drawn from the plausible band rather than open-ended speculation.
- The boundary between plausible and merely possible is a judgment call, so the cone's edges are inherently contestable.
- Its tidy geometry can imply more precision or symmetry about future uncertainty than actually exists.
- Driving alternatives by varying assumptions one at a time can miss complex interactions among drivers.
- As a framing device it bounds and sorts scenarios but does not by itself supply the rich causal logic of full scenario methods.
Common pitfalls
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Applications
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Frequently asked
What is the difference between possible, plausible, and probable futures?
These are nested categories Voros built into the futures cone. Possible futures include anything that could conceivably happen as long as no law of nature is broken — the widest band. Plausible futures are a subset: those that could reasonably happen given current understanding of how the world works, and these are the ones most scenario work uses. Probable futures are narrower still, the futures likely to occur if present trends continue, and they contain the baseline projection. The cone arranges these as concentric bands so practitioners can deliberately work in the plausible space — challenging enough to stretch thinking, disciplined enough to remain defensible.
Why does the cone widen as it extends into the future?
Because uncertainty compounds over time. Near the present, the future is tightly constrained by current conditions, so the range of credible outcomes is narrow. The further out you look, the more the assumptions underpinning any projection can bend, break, or interact, and small differences in how drivers behave accumulate into large differences in outcomes. The widening shape captures this honestly: it reminds planners that a long-horizon forecast is a broad envelope of plausible futures rather than a precise point. The geometry is a communication aid, however, not a measured probability distribution, so the widening should not be read as a calibrated confidence interval.
How is the cone of plausibility different from a full scenario method?
The cone is primarily a framing and sorting device: it makes the baseline explicit, generates alternatives by varying assumptions, and classifies them by plausibility, giving a bounded set of futures and a shared vocabulary. Full scenario methods such as intuitive logics go further, weaving each retained alternative into a rich, internally consistent causal narrative with detailed driver interactions and storylines. In practice the two are complementary: the cone is often used early to bound and select a manageable set of plausible futures, and a relational scenario method is then used to develop those selected futures into fully reasoned scenarios. Bishop, Hines, and Collins catalogue both within the scenario-development family.
Sources
- 1.Voros, J. (2003). A generic foresight process framework. Foresight, 5(3), 10-21.
- 2.Bishop, P., Hines, A., & Collins, T. (2007). The current state of scenario development: an overview of techniques. Foresight, 9(1), 5-25.
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Cite this page
ScholarGate. (2026, June 23). Cone of Plausibility. ScholarGate. https://scholargate.app/futures-foresight-studies/cone-of-plausibility