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Stanine
Stanine (STAndard NINE) is a method of scaling test scores on a nine-point standard scale with a mean of five and a standard deviation of two. Some web sources attribute stanines to the U.S. Army Air Forces during World War II. Psychometric legend has it that a 1–9 scale was used because of the compactness of recording the score as a single digit but Thorndike claims that by reducing scores to just nine values, stanines "reduce the tendency to try to interpret small score differences (p. 131)". The earliest known use of stanines was by the U.S. Army Air Forces in 1943. Calculation Test scores are scaled to stanine scores using the following algorithm: # Rank results from lowest to highest # Give the lowest 4% a stanine of 1, the next 7% a stanine of 2, etc., according to the following table: The underlying basis for obtaining stanines is that a normal distribution is divided into nine intervals, each of which has a width of 0.5 standard deviations excluding the first and la ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mean
There are several kinds of mean in mathematics, especially in statistics. Each mean serves to summarize a given group of data, often to better understand the overall value ( magnitude and sign) of a given data set. For a data set, the '' arithmetic mean'', also known as "arithmetic average", is a measure of central tendency of a finite set of numbers: specifically, the sum of the values divided by the number of values. The arithmetic mean of a set of numbers ''x''1, ''x''2, ..., x''n'' is typically denoted using an overhead bar, \bar. If the data set were based on a series of observations obtained by sampling from a statistical population, the arithmetic mean is the '' sample mean'' (\bar) to distinguish it from the mean, or expected value, of the underlying distribution, the '' population mean'' (denoted \mu or \mu_x).Underhill, L.G.; Bradfield d. (1998) ''Introstat'', Juta and Company Ltd.p. 181/ref> Outside probability and statistics, a wide range of other notions of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Standard Deviation
In statistics, the standard deviation is a measure of the amount of variation or dispersion of a set of values. A low standard deviation indicates that the values tend to be close to the mean (also called the expected value) of the set, while a high standard deviation indicates that the values are spread out over a wider range. Standard deviation may be abbreviated SD, and is most commonly represented in mathematical texts and equations by the lower case Greek letter σ (sigma), for the population standard deviation, or the Latin letter '' s'', for the sample standard deviation. The standard deviation of a random variable, sample, statistical population, data set, or probability distribution is the square root of its variance. It is algebraically simpler, though in practice less robust, than the average absolute deviation. A useful property of the standard deviation is that, unlike the variance, it is expressed in the same unit as the data. The standard deviation of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United States Army Air Forces
The United States Army Air Forces (USAAF or AAF) was the major land-based aerial warfare service component of the United States Army and ''de facto'' aerial warfare service branch of the United States during and immediately after World War II (1941–1945). It was created on 20 June 1941 as successor to the previous United States Army Air Corps and is the direct predecessor of the United States Air Force, today one of the six armed forces of the United States. The AAF was a component of the United States Army, which on 2 March 1942 was divided functionally by executive order into three autonomous forces: the Army Ground Forces, the United States Army Services of Supply (which in 1943 became the Army Service Forces), and the Army Air Forces. Each of these forces had a commanding general who reported directly to the Army Chief of Staff. The AAF administered all parts of military aviation formerly distributed among the Air Corps, General Headquarters Air Force, and the ground ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
World War II
World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the World War II by country, vast majority of the world's countries—including all of the great powers—forming two opposing military alliances: the Allies of World War II, Allies and the Axis powers. World War II was a total war that directly involved more than 100 million Military personnel, personnel from more than 30 countries. The major participants in the war threw their entire economic, industrial, and scientific capabilities behind the war effort, blurring the distinction between civilian and military resources. Air warfare of World War II, Aircraft played a major role in the conflict, enabling the strategic bombing of population centres and deploying the Atomic bombings of Hiroshima and Nagasaki, only two nuclear weapons ever used in war. World War II was by far the List of wars by death toll, deadliest conflict in hu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Normal Distribution
In statistics, a normal distribution or Gaussian distribution is a type of continuous probability distribution for a real-valued random variable. The general form of its probability density function is : f(x) = \frac e^ The parameter \mu is the mean or expectation of the distribution (and also its median and mode), while the parameter \sigma is its standard deviation. The variance of the distribution is \sigma^2. A random variable with a Gaussian distribution is said to be normally distributed, and is called a normal deviate. Normal distributions are important in statistics and are often used in the natural and social sciences to represent real-valued random variables whose distributions are not known. Their importance is partly due to the central limit theorem. It states that, under some conditions, the average of many samples (observations) of a random variable with finite mean and variance is itself a random variable—whose distribution converges to a normal d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
University Of Alberta
The University of Alberta, also known as U of A or UAlberta, is a Public university, public research university located in Edmonton, Alberta, Canada. It was founded in 1908 by Alexander Cameron Rutherford,"A Gentleman of Strathcona – Alexander Cameron Rutherford", Douglas R. Babcock, 1989, The University of Calgary Press, 2500 University Drive NW, Calgary, Alberta, Canada, the first premier of Alberta, and Henry Marshall Tory,"Henry Marshall Tory, A Biography", originally published 1954, current edition January 1992, E.A. Corbett, Toronto: Ryerson Press, the university's first president. It was enabled through the Post-secondary Learning Act''.'' The university is considered a "comprehensive academic and research university" (CARU), which means that it offers a range of academic and professional programs that generally lead to undergraduate and graduate level credentials. The university comprises four campuses in Edmonton, an Augustana Campus in Camrose, Alberta, Camrose, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Edmonton, Alberta
Edmonton ( ) is the capital city of the Canadian province of Alberta. Edmonton is situated on the North Saskatchewan River and is the centre of the Edmonton Metropolitan Region, which is surrounded by Alberta's central region. The city anchors the north end of what Statistics Canada defines as the " Calgary–Edmonton Corridor". As of 2021, Edmonton had a city population of 1,010,899 and a metropolitan population of 1,418,118, making it the fifth-largest city and sixth-largest metropolitan area (CMA) in Canada. Edmonton is North America's northernmost large city and metropolitan area comprising over one million people each. A resident of Edmonton is known as an ''Edmontonian''. Edmonton's historic growth has been facilitated through the absorption of five adjacent urban municipalities ( Strathcona, North Edmonton, West Edmonton, Beverly and Jasper Place) hus Edmonton is said to be a combination of two cities, two towns and two villages./ref> in addition to a series ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Educational Records Bureau
Educational Records Bureau (ERB) is an educational services Non-profit Organization that offers assessments for both admission and achievement for independent and selective public schools for Pre K-grade 12. ERB was founded in 1927, and is headquartered in New York City New York, often called New York City or NYC, is the List of United States cities by population, most populous city in the United States. With a 2020 population of 8,804,190 distributed over , New York City is also the L ... with over 2000 independent school and public school members globally. Leadership The organization is governed by a dedicated board of trustees. Testing/assessment programs ERB was mentioned in a ''New York Times'' article in 2011 after about 7000 (or 17%) of tested students had incorrect scores due to an error in use of a scoring key. Commenting on the effect in the New York Times, David F. Clune, president of ERB, stated, ''“It is a lesson we all learn at ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NZCER
The New Zealand Council for Educational Research (NZCER) is an independent, educational research organisation that provides educators, students, parents, policy makers, and the public with innovative and independent research, analysis, and advice. Established in 1934 through grants from the Carnegie Corporation, it became a statutory body in 1945 and now operates under the NZCER Act 1972 (and amendments). It is not formally attached to any government department, university, or other educational organisation. Under Section 13 of the NZCER Act, the organisation is required to: *foster the study of, and research into, educational and other like matters; *prepare and publish such reports on these matters as may in its opinion be necessary or of value to teachers or other persons; *furnish information, advice, and assistance to persons and organisations concerned with education or similar matters. NZCER conducts educational research and evaluation, and publishes reports. It provides i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sten Scores
The results for some scales of some psychometric instruments are returned as sten scores, sten being an abbreviation for 'Standard Ten' and thus closely related to stanine scores. Definition A sten score indicates an individual's approximate position (as a range of values) with respect to the population of values and, therefore, to other people in that population. The individual sten scores are defined by reference to a standard normal distribution. Unlike stanine scores, which have a midpoint of five, sten scores have no midpoint (the midpoint is the value 5.5). Like stanines, individual sten scores are demarcated by half standard deviations. Thus, a sten score of 5 includes all standard scores from -.5 to zero and is centered at -0.25 and a sten score of 4 includes all standard scores from -1.0 to -0.5 and is centered at -0.75. A sten score of 1 includes all standard scores below -2.0. Sten scores of 6-10 "mirror" scores 5-1. The table below shows the standard scores th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Normal Score
The term normal score is used with two different meanings in statistics. One of them relates to creating a single value which can be treated as if it had arisen from a standard normal distribution (zero mean, unit variance). The second one relates to assigning alternative values to data points within a dataset, with the broad intention of creating data values than can be interpreted as being approximations for values that might have been observed had the data arisen from a standard normal distribution. The first meaning is as an alternative name for the standard score or z score, where values are standardised by subtracting the sample or estimated mean and dividing by the sample or other estimate of the standard deviation. Particularly in applications where the name "normal score" is used, there is usually a presumption that the value can be referred to a table of standard normal probabilities as a means of providing a significance test of some hypothesis, such as a difference in m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
