All articles starting with E
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Expectations hypothesis
The expectations hypothesis of the term structure holds that long bond yields equal the average expected short-term rate plus a risk premium, a theory widely tested and often rejected.
Expected calibration error
Expected calibration error (ECE) is a widely used machine learning metric, introduced at Cornell in 2017, that measures the gap between a model's stated confidence and its actual accuracy.
Expected credit loss
Expected credit loss is an accounting estimate of credit losses on a financial asset, computed as a probability-weighted amount and introduced in IFRS 9, effective from 2018.
Expected improvement
Expected improvement (EI) is an acquisition function in Bayesian optimization that picks the next evaluation where the expected gain over the best value so far is largest.
Expected information gain
Expected information gain is a criterion in Bayesian experimental design measuring how much an experiment reduces uncertainty about unknown parameters; pioneered by Dennis Lindley in 1956.
Expected shortfall
Expected shortfall, also known as conditional value-at-risk (CVaR), is the average loss in a portfolio's worst cases beyond Value-at-Risk, used in Basel III bank capital rules.
Expected utility hypothesis
The expected utility hypothesis, also called expected utility theory, says a rational decision maker chooses among risky options by picking the act with the highest expected utility.
Expected value
The expected value, also called the mathematical expectation or mean, is the probability-weighted average of a random variable over repeated trials. Blaise Pascal introduced the concept in 1654.
Expected value of sample information
The expected value of sample information (EVSI) is a decision-theoretic measure of the average worth of a proposed study, the expected gain from updating a decision with its data.
Expectile regression
Expectile regression estimates conditional expectiles, asymmetric least-squares analogs of quantiles, using smooth squared loss that is computationally simpler than quantile regression and carries tail magnitude information.
Expedia
Expedia, also known as Expedia.com, is an American online travel agency and technology company launched by Microsoft in 1996, now one of the world's largest travel booking platforms.
Expedia Group
Expedia Group, also known as Expedia, Inc, is an American online travel company headquartered in Seattle. Founded as a Microsoft division in 1996, it operates Expedia, Hotels.com, and Vrbo.
Expedited partner therapy
Expedited partner therapy (EPT) is the practice of treating the sex partners of patients with chlamydia or gonorrhea by giving the patient medication or prescriptions for the partners without examining them.
Expedition 1
Expedition 1, also known as Expedition One, was the first crew to live aboard the International Space Station, arriving November 2, 2000, and starting 25 years of continuous human presence.
Expedition 74
Expedition 74 was the 74th long-duration expedition to the International Space Station, from December 2025 to July 2026, commanded by Michael Fincke and then Sergey Kud-Sverchkov.
Expedition 75
Expedition 75 is the 75th long-duration crew mission to the International Space Station, a roughly eight-month increment commanded by cosmonaut Pyotr Dubrov that began on July 26, 2026.
Expedition Everest
Expedition Everest – Legend of the Forbidden Mountain is a Vekoma steel roller coaster at Disney's Animal Kingdom, opened April 7, 2006, themed as a Himalayan train ride with a Yeti animatronic; its just-under-200-foot mountain is Florida's tallest.
Expedition of Álvar Núñez Cabeza de Vaca
The expedition of Álvar Núñez Cabeza de Vaca was a 1527–1536 Spanish venture to colonize the Gulf coast, ending with four castaways walking from Texas to Mexico.
Expedition of Henu to Punt
The Expedition of Henu to Punt was a Red Sea trading voyage sent by Mentuhotep III around 2000 BC and commanded by his steward Henenu, recorded in a Wadi Hammamat inscription.
Expedition of Herkhuf to Irtjet
The expedition of Herkhuf to Irtjet records the Aswan official Herkhuf's journeys through Lower Nubian Irtjet under Merenre I and Pepi II, known from his tomb inscriptions.
Expedition of Hernán Cortés
The Expedition of Hernán Cortés (Expedición de Hernán Cortés) was a private armed enterprise organized in Cuba in 1518 that conquered the Aztec capital Tenochtitlan in 1521.
Expedition of Pablo Morillo (Pacificating Army)
The Expedition of Pablo Morillo (Expedición Pacificadora de Morillo) was a Spanish army of about 11,000 veterans sent in 1815 to reconquer Venezuela and New Granada.
Expedition of Pedro de Mendoza and first Buenos Aires
The Expedition of Pedro de Mendoza (Expedición al Río de la Plata) was a Spanish venture sent by Charles V to the Río de la Plata in 1535.
Expedition of the Liberating Army to Peru
The Expedition of the Liberating Army to Peru (Expedición Libertadora del Perú) was a joint Chilean and Argentine operation led by José de San Martín that occupied Lima in 1821.
Expedition of the Thousand
The Expedition of the Thousand (Spedizione dei Mille) was Giuseppe Garibaldi's 1860 volunteer campaign that landed in Sicily and overthrew the Kingdom of the Two Sicilies.
Expedition of Usama ibn Zayd
The Expedition of Usama ibn Zayd (سرية أسامة بن زيد) was a raid into Byzantine Syria ordered by Muhammad in 632 and led by Usama ibn Zayd.
Expedition of Weni to the quarries
The Expedition of Weni to the quarries was a series of stone-quarrying missions led by the official Weni under Egyptian kings Pepi I and Merenre.
Expedition to Punt
The expedition to Punt was a trading voyage sent by pharaonic Egypt to Punt, a land rich in incense and gold, first recorded around 2500 BCE.
Expedition to Punt of Hatshepsut
The expedition to Punt of Hatshepsut was a naval trading voyage sent by pharaoh Hatshepsut to the land of Punt by Year 9 of her reign, chiefly to bring back live myrrh trees.
Expedition to Tabuk
The Expedition to Tabuk (غزوة تبوك) was Muhammad's final military campaign, launched in Rajab AH 9 with about 30,000 men; no Byzantine army appeared and no battle occurred.