## Estimated date of delivery

The estimated date of delivery, also known as expected date of confinement, and estimated due date or simply due date, is a term describing the estimated delivery date for a pregnant woman. Normal pregnancies last between 37 and 42 weeks.

## Five-minute rule

In computer science, the five-minute rule is a rule of thumb for deciding whether a data item should be kept in memory, or stored on disk and read back into memory when required. It was first formulated by Jim Gray and Gianfranco Putzolu in 1985, ...

## Freedman–Diaconis rule

In statistics, the Freedman–Diaconis rule can be used to select the width of the bins to be used in a histogram. It is named after David A. Freedman and Persi Diaconis. For a set of empirical measurements sampled from some probability distributio ...

## Fried's rule

## Haitz's law

Haitzs law is an observation and forecast about the steady improvement, over many years, of light-emitting diodes. It claims that every decade, the cost per lumen unit of useful light emitted falls by a factor of 10, and the amount of light gener ...

## Haldane's rule

Haldanes rule is an observation about the early stage of speciation, formulated in 1922 by the British evolutionary biologist J.B.S. Haldane, that states that if in a species hybrid only one sex is inviable or sterile, that sex is more likely to ...

## Heuristic argument

A heuristic argument is an argument that reasons from the value of a method or principle that has been shown experimentally to be useful or convincing in learning, discovery and problem-solving, but whose line of reasoning involves key oversimpli ...

## Huckel's rule

In organic chemistry, Huckels rule estimates whether a planar ring molecule will have aromatic properties. The quantum mechanical basis for its formulation was first worked out by physical chemist Erich Huckel in 1931. The succinct expression as ...

## Hy's law

Hys law is a rule of thumb that a patient is at high risk of a fatal drug-induced liver injury if given a medication that causes hepatocellular injury with jaundice. The law is based on observations by Hy Zimmerman, a major scholar of drug-induce ...

## I before E except after C

I before E, except after C is a mnemonic rule of thumb for English spelling. If one is not sure whether a word is spelled with the sequence ei or ie, the rhyme suggests that the correct order is ie unless the preceding letter is c, in which case ...

## Joy's law (computing)

In computing, Joys law, first formulated by Sun Microsystems co-founder Bill Joy in 1983, states that the peak computer speed doubles each year and thus is given by a simple function of time. Specifically, S = 2 Y − 1984, {\displaystyle S=2^{Y-19 ...

In photography, filmography and other visual arts, lead room, or sometimes nose room, is the space in front, and in the direction of, moving or stationary subjects. Well-composed shots leave space in the direction the subject is facing or moving. ...

## Lipinski's rule of five

Lipinskis rule of five, also known as Pfizers rule of five or simply the rule of five, is a rule of thumb to evaluate druglikeness or determine if a chemical compound with a certain pharmacological or biological activity has chemical properties a ...

## Looney 11 rule

In lunar photography, the Looney 11 rule is a method of estimating correct exposures without a light meter. For daylight photography, there is a similar rule called the Sunny 16 rule. The basic rule is: "For astronomical photos of the Moons surfa ...

## Markovnikov's rule

In organic chemistry, Markovnikovs rule or Markownikoffs rule describes the outcome of some addition reactions. The rule was formulated by Russian chemist Vladimir Markovnikov in 1870.

## Moore's law

Moores law is the observation that the number of transistors in a dense integrated circuit doubles about every two years. The observation is named after Gordon Moore, the co-founder of Fairchild Semiconductor and was the CEO of Intel, whose 1965 ...

## Moore's second law

Rocks law or Moores second law, named for Arthur Rock or Gordon Moore, says that the cost of a semiconductor chip fabrication plant doubles every four years. As of 2015, the price had already reached about 14 billion US dollars. Rocks law can be ...

## Octet rule

The octet rule is a chemical rule of thumb that reflects the observation that elements tend to bond in such a way that each atom has eight electrons in its valence shell, giving it the same electronic configuration as a noble gas. The rule is esp ...

## Okun's law

In economics, Okuns law is an empirically observed relationship between unemployment and losses in a countrys production. The "gap version" states that for every 1% increase in the unemployment rate, a countrys GDP will be roughly an additional 2 ...

## One in ten rule

In statistics, the one in ten rule is a rule of thumb for how many predictor parameters can be estimated from data when doing regression analysis while keeping the risk of overfitting low. The rule states that one predictive variable can be studi ...

## Orme's law

Ormes law is a rule of thumb to assist modelers when they design an electric power system for their radio-controlled model. Ormes law simply recommends the use of one NiMH rechargeable battery cell for every 35 square inches of wing area for spor ...

## Pareto principle

The Pareto principle states that, for many events, roughly 80% of the effects come from 20% of the causes. Management consultant Joseph M. Juran suggested the principle and named it after Italian economist Vilfredo Pareto, who noted the 80/20 con ...

## Pie rule

The pie rule, sometimes referred to as the swap rule, is a rule used to balance abstract strategy games where a first-move advantage has been demonstrated. After the first move is made in a game that uses the pie rule, the second player must sele ...

## Redshift (theory)

Redshift is a techno-economic theory suggesting hypersegmentation of information technology markets based on whether individual computing needs are over or under-served by Moores law, which predicts the doubling of computing transistors every two ...

## Right-hand rule

In mathematics and physics, the right-hand rule is a common mnemonic for understanding orientation of axes in three-dimensional space. Most of the various left- and right-hand rules arise from the fact that the three axes of three-dimensional spa ...

## Rule of 72

In finance, the rule of 72, the rule of 70 and the rule of 69.3 are methods for estimating an investments doubling time. The rule number is divided by the interest percentage per period to obtain the approximate number of periods required for dou ...

## Rule of thirds

The rule of thirds is a "rule of thumb" or guideline which applies to the process of composing visual images such as designs, films, paintings, and photographs. The guideline proposes that an image should be imagined as divided into nine equal pa ...

## Rule of thirds (diving)

In scuba diving, the rule of thirds is a rule of thumb used by divers to plan dives so they have enough breathing gas remaining in their diving cylinder at the end of the dive to be able to complete the dive safely. This rule generally only appli ...

## Rule of three (economics)

The rule of three in business and economics is a rule of thumb suggesting that there are always three major competitors in any free market within any one industry. This was put forward by Bruce Henderson of the Boston Consulting Group in 1976, an ...

## Rule of twelfths

The rule of twelfths is an approximation to a sine curve. It can be used as a rule of thumb for estimating a changing quantity where both the quantity and the steps are easily divisible by 12. Typical uses are predicting the height of the tide or ...

## Sturges' rule

## Sunny 16 rule

In photography, the sunny 16 rule is a method of estimating correct daylight exposures without a light meter. Apart from the obvious advantage of independence from a light meter, the sunny 16 rule can also aid in achieving correct exposure of dif ...

## Swanson's law

Swansons law is the observation that the price of solar photovoltaic modules tends to drop 20 percent for every doubling of cumulative shipped volume. At present rates, costs go down 75% about every 10 years. It is named after Richard Swanson, th ...

## Two-second rule

The two-second rule is a rule of thumb by which a driver may maintain a safe trailing distance at any speed. The rule is that a driver should ideally stay at least two seconds behind any vehicle that is directly in front of his or her vehicle. It ...

## Wirth's law

Wirths law is an adage on computer performance which states that software is getting slower more rapidly than hardware is becoming faster. The adage is named after Niklaus Wirth, who discussed it in his 1995 article "A Plea for Lean Software".

## Yes, and.

"Yes, and.", also referred to as "Yes, and." thinking is a rule-of-thumb in improvisational comedy that suggests that a participant should accept what another participant has stated and then expand on that line of thinking. It is also used in bus ...

## Young's rule

Valerie Hoffman is Professor and Head of the Department of Religion at the University of Illinois at Urbana-Champaign and specialises in Islamic thought and practice. She received her BA in Anthropology from the University of Pennsylvania and her ...

## Outline of science

The following outline is provided as a topical overview of science: Science is both the systematic effort of acquiring knowledge through observation, experimentation and reasoning, and the body of knowledge thus acquired. The word "science" comes ...

## Sociology of knowledge

The sociology of knowledge is the study of the relationship between human thought and the social context within which it arises, and of the effects that prevailing ideas have on societies. It is not a specialized area of sociology but instead dea ...

## Activist knowledge

Activist knowledge or dissident knowledge, refers to the ideological and ideational aspects of social movements such as challenging or reformulating dominant political ideas and ideologies, and developing new concepts, thoughts and meanings throu ...

## Celestial Emporium of Benevolent Knowledge

Celestial Emporium of Benevolent Knowledge is a fictitious taxonomy of animals described by the writer Jorge Luis Borges in his 1942 essay "The Analytical Language of John Wilkins". Wilkins, a 17th-century philosopher, had proposed a universal la ...

## Collective memory

Collective memory refers to the shared pool of memories, knowledge and information of a social group that is significantly associated with the groups identity. The English phrase "collective memory" and the equivalent French phrase la memoire col ...

## Collective representations

Collective representations are concepts, ideas, categories and beliefs that do not belong to isolated individuals, but are instead the product of a social collectivity. Durkheim originated the term collective representations to emphasise the way ...

## Folksonomy

Folksonomy is a classification system in which end users apply public tags to online items, typically to make those items easier for themselves or others to find later. Over time, this can give rise to a classification system based on those tags ...

## Intelligentsia

The intelligentsia is a status class of educated people engaged in the complex mental labours that critique, guide, and lead in shaping the culture and politics of their society. As a status class, the intelligentsia includes artists, teachers an ...

## Les Lieux de Memoire

A lieu de memoire is a concept popularized by the French historian Pierre Nora in his three-volume collection Les Lieux de Memoire.

## Mainstream

The mainstream is the prevalent current thought that is widespread. It includes all popular culture and media culture, typically disseminated by mass media. This word is sometimes used in a pejorative sense by subcultures who view ostensibly main ...

## Problems of a Sociology of Knowledge

Problems of a Sociology of Knowledge is a 1924 essay by the German philosopher, sociologist, and anthropologist Max Scheler. It was translated into English by Manfred S. Frings and published by Routledge & Kegan Paul in 1980. It reappeared in exp ...

## Sociology of knowledge approach to discourse

The sociology of knowledge approach to discourse is a social science research programme for studying discourse developed by Reiner Keller in order to analyze knowledge relationships and conditions in society. SKAD stems from the sociology of know ...