"There are unknown unknowns" is a phrase from a response United States Secretary of Defense Donald Rumsfeld gave to a question at a U.S. Department of Defense (DoD) news briefing on February 12, 2002, about the lack of evidence linking the government of Iraq with the supply of weapons of mass destruction to terrorist groups. [1] Rumsfeld stated:
Reports that say that something hasn't happened are always interesting to me, because as we know, there are known knowns; there are things we know we know. We also know there are known unknowns; that is to say we know there are some things we do not know. But there are also unknown unknowns—the ones we don't know we don't know. And if one looks throughout the history of our country and other free countries, it is the latter category that tends to be the difficult ones. [1]
The statement became the subject of much commentary. In The Decision Book (2013), author Mikael Krogerus refers to it as the "Rumsfeld matrix". [2] The statement also features in a 2013 documentary film, The Unknown Known , directed by Errol Morris. [3]
Known unknowns refers to "risks you are aware of, such as canceled flights", [4] whereas unknown unknowns are risks that come from situations that are so unexpected that they would not be considered.
With respect to awareness and understanding, unknown unknowns can be compared to other types of problems in the following matrix:
Aware | Not aware | |
---|---|---|
Understand | Known knowns: Things we are aware of and understand | Unknown knowns: Things we are not aware of but do understand or know implicitly |
Don't understand | Known unknowns: Things we are aware of but don't understand | Unknown unknowns: Things we are neither aware of nor understand |
Rumsfeld's statement brought attention to the concepts of known knowns, known unknowns, and unknown unknowns, but national security and intelligence professionals have long used an analysis technique referred to as the Johari window. The idea of unknown unknowns was created in 1955 by two American psychologists, Joseph Luft and Harrington Ingham in their development of the Johari window.[ citation needed ] They used it as a technique to help people better understand their relationship with themselves as well as others.
The term was also commonly used inside NASA. [6] Rumsfeld cited NASA administrator William Graham in his memoir; he wrote that he had first heard "a variant of the phrase" from Graham when they served together on the Commission to Assess the Ballistic Missile Threat to the United States during the late 1990s. [7] Kirk Borne, an astrophysicist who was employed as a data scientist at NASA Goddard Space Flight Center at the time, said in an April 2013 TED talk that he had used the phrase "unknown unknowns" in a talk to personnel at the Homeland Security Transition Planning Office a few days prior to Rumsfeld's remarks, and speculated that the term may have percolated up to Rumsfeld and other high-ranking officials in the Defense Department. [8]
The terms "known unknowns" and "unknown unknowns" are often used in project management and strategic planning [9] circles.
Contemporary usage is largely consistent with the earliest known usages. For example, the term was used in evidence given to the British Columbia Royal Commission of Inquiry into Uranium Mining in 1979:
Site conditions always pose unknowns, or uncertainties, which may become known during construction or operation to the detriment of the facility and possibly lead to damage of the environment or endanger public health and safety. The risk posed by unknowns is somewhat dependent on the nature of the unknown relative to past experience. This has led me to classify unknowns into one of the following two types: 1. known unknowns (expected or foreseeable conditions), which can be reasonably anticipated but not quantified based on past experience as exemplified by case histories (in Appendix A) and 2. Unknown unknowns (unexpected or unforeseeable conditions), which pose a potentially greater risk simply because they cannot be anticipated based on past experience or investigation. Known unknowns result from recognized but poorly understood phenomena. On the other hand, unknown unknowns are phenomena which cannot be expected because there has been no prior experience or theoretical basis for expecting the phenomena. [10]
The term also appeared in a 1982 New Yorker article on the aerospace industry, which cites the example of metal fatigue, the cause of crashes in de Havilland Comet airliners in the 1950s. [11]
Canadian columnist Mark Steyn called it "in fact a brilliant distillation of quite a complex matter". [12] Australian economist and blogger John Quiggin wrote: "Although the language may be tortured, the basic point is both valid and important." [13]
Psychoanalytic philosopher Slavoj Žižek says that beyond these three categories there is a fourth, the unknown known, that which one intentionally refuses to acknowledge that one knows: "If Rumsfeld thinks that the main dangers in the confrontation with Iraq were the 'unknown unknowns', that is, the threats from Saddam whose nature we cannot even suspect, then the Abu Ghraib scandal shows that the main dangers lie in the "unknown knowns"—the disavowed beliefs, suppositions and obscene practices we pretend not to know about, even though they form the background of our public values." [14]
German sociologists Christopher Daase and Oliver Kessler agreed that the cognitive frame for political practice may be determined by the relationship between "what we know, what we do not know, what we cannot know", but stated that Rumsfeld left out "what we do not like to know". [15]
The event has been used in multiple books to discuss risk assessment. [3] [16]
Rumsfeld named his 2011 autobiography Known and Unknown: A Memoir . In the author's note at the start of the book, he expressly acknowledges the source of his memoir's title and mentions a few examples of his statement's prominence. [17] The Unknown Known is the title of Errol Morris's 2013 biographical documentary film about Rumsfeld. [18] In it, Rumsfeld initially defines "unknown knowns" as "the things you think you know, that it turns out you did not", and toward the end of the film he defines the term as "things that you know, that you don't know you know". [19]
Rumsfeld's comment earned the 2003 Foot in Mouth Award from the British Plain English Campaign. [20]
The concept of unknown unknowns, a recognition of things that are not only outside of one's knowledge but outside of one's awareness, has historical precedence in Persian literature. A notable example is a poem from the 14th-century Ibn Yamin, which categorizes knowledge and ignorance into four states: [21] [22]
In the unknown unknowns category, compound ignorance refers to ignorance that is compounded by the lack of self-awareness about one's limitations.
The term "known unknowns" has been applied to the identification of chemical substances using analytical chemistry approaches, specifically mass spectrometry. In many cases, an unknown to an investigator that is detected in an experiment is actually known in the chemical literature, a reference database, or an Internet resource. These types of compounds are termed "known unknowns". The term was originally coined by Little et al. [23] and reported a number of times in the literature since then as a general approach. [24] [25] [26] [27]
Donald Henry Rumsfeld was an American politician, government official and businessman who served as secretary of defense from 1975 to 1977 under President Gerald Ford, and again from 2001 to 2006 under President George W. Bush. He was both the youngest and the oldest secretary of defense. Additionally, Rumsfeld was a four-term U.S. Congressman from Illinois (1963–1969), director of the Office of Economic Opportunity (1969–1970), counselor to the president (1969–1973), the U.S. Representative to NATO (1973–1974), and the White House Chief of Staff (1974–1975). Between his terms as secretary of defense, he served as the CEO and chairman of several companies.
Argument from ignorance, also known as appeal to ignorance, is a fallacy in informal logic. The fallacy is committed when one asserts that a proposition is true because it has not yet been proven false or a proposition is false because it has not yet been proven true. If a proposition has not yet been proven true, one is not entitled to conclude, solely on that basis, that it is false, and if a proposition has not yet been proven false, one is not entitled to conclude, solely on that basis, that it is true. Another way of expressing this is that a proposition is true only if proven true, and a proposition is false only if proven false. If no proof is offered, then the proposition can be called unproven, undecided, inconclusive, an open problem or a conjecture. In debates, appealing to ignorance is sometimes an attempt to shift the burden of proof. The term was likely coined by philosopher John Locke in the late 17th century.
Uncertainty or incertitude refers to epistemic situations involving imperfect or unknown information. It applies to predictions of future events, to physical measurements that are already made, or to the unknown. Uncertainty arises in partially observable or stochastic environments, as well as due to ignorance, indolence, or both. It arises in any number of fields, including insurance, philosophy, physics, statistics, economics, finance, medicine, psychology, sociology, engineering, metrology, meteorology, ecology and information science.
Found poetry is a type of poetry created by taking words, phrases, and sometimes whole passages from other sources and reframing them by making changes in spacing and lines, or by adding or deleting text, thus imparting new meaning. The resulting poem can be defined as treated: changed in a profound and systematic manner; or untreated: virtually unchanged from the order, syntax and meaning of the poem.
The Sortino ratio measures the risk-adjusted return of an investment asset, portfolio, or strategy. It is a modification of the Sharpe ratio but penalizes only those returns falling below a user-specified target or required rate of return, while the Sharpe ratio penalizes both upside and downside volatility equally. Though both ratios measure an investment's risk-adjusted return, they do so in significantly different ways that will frequently lead to differing conclusions as to the true nature of the investment's return-generating efficiency.
The effects of spaceflight on the human body are complex and largely harmful over both short and long term. Significant adverse effects of long-term weightlessness include muscle atrophy and deterioration of the skeleton. Other significant effects include a slowing of cardiovascular system functions, decreased production of red blood cells, balance disorders, eyesight disorders and changes in the immune system. Additional symptoms include fluid redistribution, loss of body mass, nasal congestion, sleep disturbance, and excess flatulence. A 2024 assessment noted that "well-known problems include bone loss, heightened cancer risk, vision impairment, weakened immune systems, and mental health issues... [y]et what’s going on at a molecular level hasn’t always been clear", arousing concerns especially vis a vis private and commercial spaceflight now occurring without any scientific or medical research being conducted among those populations regarding effects.
Klaus Biemann was an Austrian-American professor of chemistry at the Massachusetts Institute of Technology. His work centered on structural analysis in organic and biochemistry. He has been called the "father of organic mass spectrometry" but was particularly noted for his role in advancing protein sequencing with tandem mass spectrometry following pioneering work conducted in this area by Michael Barber.
The black swan theory or theory of black swan events is a metaphor that describes an event that comes as a surprise, has a major effect, and is often inappropriately rationalized after the fact with the benefit of hindsight. The term is based on a Latin expression which presumed that black swans did not exist. The expression was used until around 1697 when Dutch mariners saw them in Australia. After this, the term was reinterpreted to mean an unforeseen and consequential event.
Within the sociology of knowledge, agnotology is the study of deliberate, culturally induced ignorance or doubt, typically to sell a product, influence opinion, or win favour, particularly through the publication of inaccurate or misleading scientific data (disinformation). More generally, the term includes the condition where more knowledge of a subject creates greater uncertainty.
Richard Jay Zeckhauser is an American economist and the Frank P. Ramsey Professor of Political Economy at Harvard Kennedy School at Harvard University.
Ethyldichloroarsine, sometimes abbreviated as "ED" and "CY" and also known as ethyl Dick, is an organoarsenic compound with the formula CH3CH2AsCl2. This colourless volatile liquid is a highly toxic obsolete vesicant or blister agent that was used during World War I in chemical warfare. The molecule is pyramidal with the Cl-As-Cl and C-As-Cl angles approaching 90° (see image). Ethyldichloroarsine has high chronic toxicity, similar to lewisite.
In simple terms, risk is the possibility of something bad happening. Risk involves uncertainty about the effects/implications of an activity with respect to something that humans value, often focusing on negative, undesirable consequences. Many different definitions have been proposed. One international standard definition of risk is the "effect of uncertainty on objectives".
Judith A. Curry is an American climatologist and former chair of the School of Earth and Atmospheric Sciences at the Georgia Institute of Technology. Her research interests include hurricanes, remote sensing, atmospheric modeling, polar climates, air-sea interactions, climate models, and the use of unmanned aerial vehicles for atmospheric research. She was a member of the National Research Council's Climate Research Committee, published over a hundred scientific papers, and co-edited several major works. Curry retired from academia in 2017 at age 63, coinciding with her public climate change skepticism.
Known and Unknown: A Memoir is an autobiographical book by Donald Rumsfeld published through Penguin Group USA in February 2011. It covers a variety of his experiences such as serving as a member of the United States House of Representatives in the late 60s, as a member of the Nixon and Ford administrations during the Watergate scandal and Vietnam War, and as George W. Bush's Secretary of Defense at the onset of the War on Terror.
Astronauts are exposed to approximately 72 millisieverts (mSv) while on six-month-duration missions to the International Space Station (ISS). Longer 3-year missions to Mars, however, have the potential to expose astronauts to radiation in excess of 1,000 mSv. Without the protection provided by Earth's magnetic field, the rate of exposure is dramatically increased. The risk of cancer caused by ionizing radiation is well documented at radiation doses beginning at 100 mSv and above.
The Unknown Known is a 2013 American documentary film about the political career of former U.S. Secretary of Defense and congressman Donald Rumsfeld, directed by Academy Award winning documentarian and filmmaker Errol Morris. It is a summary of 33 hours of interviews that Morris conducted with Rumsfeld over eleven separate sessions during visits to Newton, Massachusetts. The film was released on April 4, 2014, by Radius-TWC, and is dedicated to the memory of Roger Ebert.
The scientific community in the United States and Europe are primarily concerned with the possible effect of electronic cigarette use on public health. There is concern among public health experts that e-cigarettes could renormalize smoking, weaken measures to control tobacco, and serve as a gateway for smoking among youth. The public health community is divided over whether to support e-cigarettes, because their safety and efficacy for quitting smoking is unclear. Many in the public health community acknowledge the potential for their quitting smoking and decreasing harm benefits, but there remains a concern over their long-term safety and potential for a new era of users to get addicted to nicotine and then tobacco. There is concern among tobacco control academics and advocates that prevalent universal vaping "will bring its own distinct but as yet unknown health risks in the same way tobacco smoking did, as a result of chronic exposure", among other things.
Roa rumsfeldi is a species of marine ray-finned fish, a butterflyfish belonging to the family Chaetodontidae. It is the fifth known species of the genus Roa and was discovered in Anilao, Philippines in 2016. This species has vertical white and brown stripes and has a black spine on the ventral fin contrary to the other Roa specimens.
Ibn Yamin was a Persian poet who served under the Ilkhanate, Sarbadars, and Kartids.
In philosophy, unknowability is the possibility of inherently unaccessible knowledge. It addresses the epistemology of that which they cannot know. Some related concepts include the halting problem, the limits of knowledge, the unknown unknowns, and chaos theory.
Reporter:37:19 ...Because there are reports that there is no evidence of a direct link between Baghdad and some of these terrorist organizations.
Rumsfeld: Reports that say that something hasn't happened are always interesting to me...