Original Message:
Sent: 11-28-2025 12:51 PM
From: Joerg-Martin Hohberg
Subject: How do you distinguish between risk and uncertainty?
In daily language "risk" is connotated with hazard, whereas uncertainty is more neutral and includes also opportunities. This coincides with the meaning of the Latin word "riscare" which means sailing around a cape (i.e. risks of ship wrecking deliberately taken for the sake of entrepreneural rewards, e.g. by Vasca da Gama searching for spices in India).
Insisting on the term "risk" to be likewise positive ("upstream risk") or negative ("downstream risk") appears to be difficult. Hence the loose practice to speak of "risks & uncertainties" -- which should more precisely be replaced by "threats & opportunities".
Note also that usually there are many uncertainties, which don't really matter in terms of success or failure of an undertaking. Hence David Hilson coined the memo: "Risks are uncertainties that matter".
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[J.-Martin] [Hohberg]
[Dr.sc.techn, M.ASCE FED]
[Sr. Consultant, IABSE e-Learning Board]
[Bremgarten / Berne] [Switzerland]
Original Message:
Sent: 11-26-2025 09:47 AM
From: William McAnally
Subject: How do you distinguish between risk and uncertainty?
The CEBOK does a good job of distinguishing between risk and uncertainty, defining risk as "... the most likely consequence of a particular hazard or vulnerability combined with the likelihood or probability of it occurring." That definition, distinct from uncertainty, is consistent with the definition given in the Risk Primer developed by this community.
I'm not enthusiastic about the CEBOK's almost constant linking of uncertainty to risk by using the phrase "Risk and Uncertainty" instead of just "Risk." While risk includes the effects of uncertainty, each term stands on its own. Risk also includes probability and consequences but we don't lump all those words into one label. Risk is risk.
Bill Mc
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William McAnally Ph.D., P.E., BC.CE, BC.NE, F.ASCE
ENGINEER
Columbus MS
Original Message:
Sent: 11-21-2025 08:23 AM
From: Mitchell Winkler
Subject: How do you distinguish between risk and uncertainty?
I recently received a request from ASCE for my support in developing the ASCE CEC Early Career cross-discipline certification. This request prompted me to review the CEBOK, which includes a section on Risk and Uncertainty. It further prompted me to examine the distinction between risk and uncertainty. I found this reference to Frank Wright
https://news.mit.edu/2010/explained-knightian-0602
Frank Knight was an idiosyncratic economist who formalized a distinction between risk and uncertainty in his 1921 book, Risk, Uncertainty, and Profit. As Knight saw it, an ever-changing world brings new opportunities for businesses to make profits, but also means we have imperfect knowledge of future events. Therefore, according to Knight, risk applies to situations where we do not know the outcome of a given situation, but can accurately measure the odds. Uncertainty, on the other hand, applies to situations where we cannot know all the information we need in order to set accurate odds in the first place.
Searching for Frank Knight and risk and uncertainty will yield many more references.
How do you view the difference between risk and uncertainty? Sharpening this distinction would help everyone.
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Mitch Winkler P.E.(inactive), M.ASCE
Houston, TX
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