Erna Schneider Hoover

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Erna Schneider Hoover
Erna Schneider

(1926-06-19) June 19, 1926 (age 93)
Citizenship United States
Alma mater Wellesley B.A.,
Yale Ph.D.
Known forComputerized system
for phone traffic [2]
Spouse(s)Charles Wilson Hoover, Jr.
Awards National Inventors Hall of Fame, 2008 [3]
Wellesley alumni
achievement award [2]
Scientific career
Institutions Bell Labs
Thesis An Analysis of
Conditional Sentences [2]

Dr. Erna Schneider Hoover (born June 19, 1926) is an American mathematician notable for inventing a computerized telephone switching method which "revolutionized modern communication" according to several reports. [1] [4] It prevented system overloads by monitoring call center traffic and prioritizing tasks [4] on phone switching systems to enable more robust service during peak calling times. [1] At Bell Laboratories where she worked for over 32 years, [5] Hoover was described as an important pioneer for women in the field of computer technology. [2]

Americans Citizens, or natives, of the United States of America

Americans are nationals and citizens of the United States of America. Although nationals and citizens make up the majority of Americans, some dual citizens, expatriates, and permanent residents may also claim American nationality. The United States is home to people of many different ethnic origins. As a result, American culture and law does not equate nationality with race or ethnicity, but with citizenship and permanent allegiance.

Mathematician person with an extensive knowledge of mathematics

A mathematician is someone who uses an extensive knowledge of mathematics in his or her work, typically to solve mathematical problems.

Telephone exchange telecommunications system used in public switched telephone networks or in large enterprises

A telephone exchange is a telecommunications system used in the public switched telephone network or in large enterprises. An exchange consists of electronic components and in older systems also human operators that interconnect (switch) telephone subscriber lines or virtual circuits of digital systems to establish telephone calls between subscribers.


Early life

Erna Schneider was born on June 19, 1926, [1] in Irvington, New Jersey. [2] Her family lived in South Orange, New Jersey and her father was a dentist and her mother was a teacher. [2] She had a younger brother who died from polio at the age of five. [2] She loved swimming, sailing, canoeing, and was interested in science at an early age. According to one source, she read the biography of Marie Curie which suggested to her that she could succeed in a scientific field despite the prevailing ideas about gender roles at the time. [2] She graduated from Columbia High School in nearby Maplewood in 1944, which would later induct her into its hall of fame in 2007. [6]

Irvington, New Jersey Township in New Jersey, United States

Irvington is a township in Essex County, New Jersey, United States. As of the 2010 United States Census, the township had a total population of 53,926, having declined by 6,769 (−11.2%) from the 60,695 counted in the 2000 Census, which had in turn declined by 323 (−0.5%) from the 61,018 counted in the 1990 Census.

South Orange, New Jersey Township in New Jersey, United States

South Orange, officially the Township of South Orange Village, is a suburban township in Essex County, New Jersey, United States. As of the 2010 United States Census, the village's population was 16,198, reflecting a decline of 766 (-4.5%) from the 16,964 counted in the 2000 Census, which had in turn increased by 574 (+3.5%) from the 16,390 counted in the 1990 Census. Seton Hall University is located in the township.

Polio Infectious disease caused by poliovirus

Polio, short for poliomyelitis, or infantile paralysis, is an infectious disease caused by the poliovirus. In about 0.5 percent of cases there is muscle weakness resulting in an inability to move. This can occur over a few hours to a few days. The weakness most often involves the legs but may less commonly involve the muscles of the head, neck and diaphragm. Many people fully recover. In those with muscle weakness about 2 to 5 percent of children and 15 to 30 percent of adults die. Another 25 percent of people have minor symptoms such as fever and a sore throat and up to 5 percent have headache, neck stiffness and pains in the arms and legs. These people are usually back to normal within one or two weeks. In up to 70 percent of infections there are no symptoms. Years after recovery post-polio syndrome may occur, with a slow development of muscle weakness similar to that which the person had during the initial infection.

Hoover attended Wellesley College where she studied classical and medieval philosophy and history. [1] [7] [8] [9] She graduated from Wellesley in 1948 with honors, earning a bachelor's degree, and she was inducted into Phi Beta Kappa and was honored as a Durant Scholar. [2] She earned her Ph.D from Yale University in philosophy and foundations of mathematics in 1951. [1] [7]

Wellesley College Private womens liberal arts college in Massachusetts

Wellesley College is a private women's liberal arts college in Wellesley, Massachusetts. Founded in 1870 by Henry and Pauline Durant, it is a member of the original Seven Sisters Colleges. Wellesley is home to 56 departmental and interdepartmental majors spanning the liberal arts, as well as over 150 student clubs and organizations. The college also allows its students to cross-register at Massachusetts Institute of Technology, Brandeis University, Babson College and Franklin W. Olin College of Engineering. Wellesley athletes compete in the NCAA Division III New England Women's and Men's Athletic Conference.

Phi Beta Kappa Honor society for the liberal arts and sciences in the United States

The Phi Beta Kappa Society (ΦΒΚ) is the oldest academic honor society in the United States, and is often described as its most prestigious honor society, due to its long history and academic selectivity. Phi Beta Kappa aims to promote and advocate excellence in the liberal arts and sciences, and to induct the most outstanding students of arts and sciences at American colleges and universities. It was founded at the College of William and Mary on December 5, 1776 as the first collegiate Greek-letter fraternity and was among the earliest collegiate fraternal societies.

Yale University Private research university in New Haven, Connecticut, United States

Yale University is a private Ivy League research university in New Haven, Connecticut. Founded in 1701, it is the third-oldest institution of higher education in the United States and one of the nine Colonial Colleges chartered before the American Revolution. Yale consistently ranks among the top universities in the world.


Hoover was a professor at Swarthmore College from 1951 to 1954 [1] where she taught philosophy and logic. [2] However, she had been unable to win a tenure-track position, possibly because of her gender and marital status, according to one view. In 1953, she married Charles Wilson Hoover, Jr., and he was very supportive of his wife's career pursuits. [2] In 1954, she joined Bell Labs as a senior technical associate, and was promoted in 1956. According to one source, the internal training program was the "equivalent of a master's degree in computer science." [2] Switching systems were moving from electronic to computer-based technologies. Problems happened when a call center would be inundated with thousands of calls in a short amount of time, overwhelming the unreliable electronic relays, and causing the entire system to "freeze up." [2]

Swarthmore College Liberal arts college in Swarthmore, Pennsylvania

Swarthmore College is a private liberal arts college in Swarthmore, Pennsylvania. Founded in 1864, with its first classes being held in 1869, Swarthmore was one of the earliest coeducational colleges in the United States. It was established to be a college "...under the care of Friends, at which an education may be obtained equal to that of the best institutions of learning in our country." By 1906, Swarthmore had dropped its religious affiliation and became officially non-sectarian.

Philosophy The rational investigation of the truths and principles of being, knowledge, or conduct.

Philosophy is the study of general and fundamental questions about existence, knowledge, values, reason, mind, and language. Such questions are often posed as problems to be studied or resolved. The term was probably coined by Pythagoras. Philosophical methods include questioning, critical discussion, rational argument, and systematic presentation. Classic philosophical questions include: Is it possible to know anything and to prove it? What is most real? Philosophers also pose more practical and concrete questions such as: Is there a best way to live? Is it better to be just or unjust? Do humans have free will?

Logic Study of inference and truth

Logic is the systematic study of the form of valid inference, and the most general laws of truth. A valid inference is one where there is a specific relation of logical support between the assumptions of the inference and its conclusion. In ordinary discourse, inferences may be signified by words such as therefore, thus, hence, ergo, and so on.

Hoover used her knowledge of symbolic logic and feedback theory to program the control mechanisms of a call center to use data about incoming calls to impose order on the whole system. [2] It used computer electronic methods to monitor the frequency of incoming calls [10] at different times. [11] Her method gave priority to processes that were concerned with the input and output of the switch over processes that were less important such as record keeping and billing. [2] [7] The computer, as a result, would adjust the call center's acceptance rate automatically, greatly reducing the overloading problem. [9] The system became known as stored program control. [11]

Feedback process in which information about the past or the present influences the same phenomenon in the present or future;occurs when outputs of a system are routed back as inputs as part of a chain of cause-and-effect that forms a circuit or loop

Feedback occurs when outputs of a system are routed back as inputs as part of a chain of cause-and-effect that forms a circuit or loop. The system can then be said to feed back into itself. The notion of cause-and-effect has to be handled carefully when applied to feedback systems:

Simple causal reasoning about a feedback system is difficult because the first system influences the second and second system influences the first, leading to a circular argument. This makes reasoning based upon cause and effect tricky, and it is necessary to analyze the system as a whole.

Stored program control (SPC) was a telecommunications technology used for telephone exchanges controlled by a computer program stored in the memory of the switching system. SPC was the enabling technology of electronic switching systems (ESS) developed in the Bell System in the 1950s, and may be considered the third generation of switching technology. Stored program control was invented by Bell Labs scientist Erna Schneider Hoover in 1954 who reasoned that computer software could control the connection of telephone calls.

Hoover's thinking about the invention happened while she was in a hospital recuperating after having given birth to her second daughter, according to several sources. [11] [7] [12] Lawyers for Bell Labs handling the patent had to go to her house to visit her while she was on maternity leave so that she could sign the papers. [1] The result of the invention was much more robust service to callers during peak load times:

To my mind it was kind of common sense ... I designed the executive program for handling situations when there are too many calls, to keep it operating efficiently without hanging up on itself. Basically it was designed to keep the machine from throwing up its hands and going berserk.

Erna Schneider Hoover, 2008 [4]
Hoover is a lifelong advocate for higher education. As board member of The College of New Jersey, she was instrumental in its efforts to attract the state's best students, hire women faculty, and win more state aid. The College of New Jersey (TCNJ) 27.jpg
Hoover is a lifelong advocate for higher education. As board member of The College of New Jersey, she was instrumental in its efforts to attract the state's best students, hire women faculty, and win more state aid.

For her invention, termed Feedback Control Monitor for Stored Program Data Processing System, Hoover was awarded patent #3,623,007 in November 1971, one of the first software patents ever issued. [10] The patent was applied for in 1967 and issued in 1971. [2] [13] As a result of her invention, she became the first woman supervisor of a technical department at Bell Labs. [4] [7] She headed the operations support department in 1987. [5] The principles of her invention are still being used in telecommunications equipment in the 21st century.

Hoover worked on various high-level applications such as research radar control programs of the Safeguard Anti-Ballistic Missile System, which were systems to intercept incoming intercontinental ballistic missile warheads. [2] Her department worked on artificial intelligence methods, large databases, and transactional software to support large telephone networks. [2] She worked at Bell Labs for 32 years until retiring in 1987. [5] In addition, she served on the boards of higher education organizations in New Jersey. [2] As a member of the board of Trustees of The College of New Jersey, she was described as a visionary who was instrumental in increasing women faculty as well as enrolling the "best prepared high school graduates" in the state, and she helped build the college into a respected institution of higher education by lobbying extensively for state funding. [14]


She was awarded one of the first patents for computer software. [2] She was elected as a member of the National Inventors Hall of Fame in 2008. [11] She received the Wellesley College alumni achievement award. [2]

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  1. 1 2 3 4 5 6 7 8 "Hall of Fame -- induction info". National Inventors Hall of Fame. 2008. Archived from the original on 2012-04-28. Retrieved 2012-06-05.
  2. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 "Erna Hoover -- Biography". World of Computer Science. 2012. Retrieved 2012-06-17.
  3. National Inventors Hall of Fame Archived 2010-07-09 at the Wayback Machine website. Accessed March 18, 2010.
  4. 1 2 3 4 Amy Ellis Nutt (June 18, 2008). "Fame calls on 2 titans of telephony in NJ". The Star-Ledger. Retrieved 2012-06-05.
  5. 1 2 3 Calvin Sims (March 9, 1987). "BELL LABS: ADAPTING TO MONOPOLY'S END". The New York Times. Retrieved 2012-06-05.
  6. Hall of Fame Archived 2018-11-18 at the Wayback Machine , Columbia High School. Accessed November 12, 2018.
  7. 1 2 3 4 5 "Erna Schneider Hoover profile". Global History Network of IEEE. 2012. Retrieved 2012-06-17.
  8. "Biography". Fact Monster. 2012-06-17. Retrieved 2012-06-17.
  9. 1 2 "Erna Schneider Hoover profile". 2012-06-17. Retrieved 2012-06-17.
  10. 1 2 Alpha Doggs (February 15, 2008). "Phone switching pioneers to be inducted in National Inventors Hall of Fame". Network World. Retrieved 2012-06-17.
  11. 1 2 3 4 "Hoover, Erna (Schneider)". Smart Computing. 2012. Retrieved 2012-06-17.
  12. "Erna Schneider Hoover Computerized Telephone Switching System". Massachusetts Institute of Technology. 2012. Retrieved 2012-06-17.
  13. See Patent #3623007 November 23, 1971
  14. "Former TCNJ Board member elected to National Inventors Hall of Fame". The College of New Jersey. February 18, 2008. Retrieved 2012-06-17.