Delta (letter) A river delta (originally, the Nile River delta) is so named because its shape approximates the upper-case letter delta (the shape is a triangle).

Despite a popular legend, this use of the word delta was not coined by Herodotus.[2] In Ancient Greek, delta represented a voiced dental plosive /d/. Zero. Historical scientists categorize the types of number systems peoples use, much the same way philologists break down languages into "analytic," "agglutinative," "inflectional," etc.

The path that leads to the discovery of "0" lies only in the most advanced type of number system, which is called "positional" because the value of a character depends on its position. Our modern way of counting is positional. The base figure "5" has a different value in 514 and in 145, determined by its position. The Romans, Greeks, Hebrews (and Aztecs and pre-Islamic Arabs and a great many others) used an "additive" system, which is fundamentally a transcription of counting.

A Roman "V" meant "five" and that's all it could mean. Positional systems have certain features in common. Fractals. LogicKo. Language in Life. List of mathematical symbols. Approximation. An approximation is anything that is similar but not exactly equal to something else.

The term can be applied to various properties (e.g. value, quantity, image, description) that are nearly but not exactly correct; similar, but not exactly the same e.g. The approximate time was 10 o'clock. In science, approximation can refer to using a simpler process or model when the correct model is difficult to use.

An approximate model is used to make calculations easier. Equals approximately (=~) New Sciences. SCIENCE. Why isn't the U.S. on the metric system? - HowStuffWorks. Many myths swirl around the metric system and U.S. involvement with it.

Let's dispel a few. First, the relationship between the metric system and the United States dates back to the 18th century, not the 1970s. Second, all countries have either fully adopted or legally sanctioned the International System of Units, or SI, the modern form of the metric system. That includes the U.S., Liberia and Myanmar, three countries often listed as the sad-sack metric losers. Finally, a country doesn't simply "turn on" on a brand-new system of weights and measures. Despite America's long history with SI units, measuring remains a mess in the States.

Mathematics. Symbolica. Probability. Methods and tools for explaining things. How investigating mediators and moderators helps explain intervention effects. How mediators and moderators help explain intervention effects 3Moderators are variables that are present among the population prior to an intervention.

9.5.1 What is heterogeneity? Home > Part 2: General methods for Cochrane reviews > 9 Analysing data and undertaking meta-analyses > 9.5 Heterogeneity > 9.5.1 What is heterogeneity?

9.5.1 What is heterogeneity? Inevitably, studies brought together in a systematic review will differ. 1471-2288-11-22.pdf. 18.7 - Cohen's Kappa Statistic for Measuring Agreement. Printer-friendly version Cohen's kappa statistic, κ , is a measure of agreement between categorical variables X and Y.

For example, kappa can be used to compare the ability of different raters to classify subjects into one of several groups. Research Rundowns. .pdf version of this page As you read educational research, you’ll encounter t-test (t) and ANOVA (F) statistics frequently.

Hopefully, you understand the basics of (statistical) significance testing as related to the null hypothesis and p values, to help you interpret results. If not, see the Significance Testing (t-tests) review for more information. In this class, we’ll consider the difference between statistical significance and practical significance, using a concept called effect size. The “Significance” Issue Most statistical measures used in educational research rely on some type of statistical significance measure to authenticate results. While most published statistical reports include information on significance, such measures can cause problems for practical interpretation.

Cohensd.xls. University of Colorado Colorado Springs. Cohen's d. Cohen's d is an effect size used to indicate the standardised difference between two means.

It can be used, for example, to accompany reporting of t-test and ANOVA results. It is also widely used in meta-analysis. Interpreting Cohen's d effect size. Tiger. Fig 1: The functions eta - , mu - , zeta -

1009.1092v10.pdf. 1009.1092v10.pdf. High Quality Visualization of <br> Biochemical Pathways in BioPath. The Man of Numbers: How Fibonacci Changed the World. By Maria Popova What Medieval mathematics have to do with remix culture, publishing entrepreneurship, and gamification. Imagine a day without numbers — how would you know when to wake up, how to call your mother, how the stock market is doing, or even how old you are? We live our lives by numbers. Ancient Egyptian Numbers. Egyptian Numbers --- Introduction --- Addition --- Multiplication --- Fractions Enter a number from 1 to 9999999 to see how the Egyptians would have written it, or enter a number to count with. In the Arabic number system, we have ten digits (from 0-9) and we can make as big a number as we want with these. List of things named after Leonhard Euler. In mathematics and physics, there are a large number of topics named in honor of Leonhard Euler, many of which include their own unique function, equation, formula, identity, number (single or sequence), or other mathematical entity.

Unfortunately, many of these entities have been given simple and ambiguous names such as Euler's function, Euler's equation, and Euler's formula. Euler's work touched upon so many fields that he is often the earliest written reference on a given matter. The 13 Most Important Numbers in the Universe - James D. Stein's Cosmic Numbers. In the 17th century, scientists understood three phases of matter—solids, liquids and gases (the discovery of plasma, the fourth phase of matter, lay centuries in the future). Simulations. Statistical Visualization. For his book The Visual Miscellaneum, David McCandless, along with Lee Byron, had a look at breakups on Facebook, according to status updates.

Canadian Social Statistics - Statistiques sociales du Canada. Updated April 13, 2014 Page révisée le 13 avril 2014. Statistical Data. Statistics. Gantt. MS Science Method. Math for America - Teacher Resources - Lesson Plans & Activities. Teachers . Recommended Links . Math . Archive. "A member of Ryerson Polytechnic Institute's Department of Engineering and Computing brings you this award-winning site about the history and operations of the abacus. Teachers - Math Data Analysis/Probability. Source: NewsHour Extra. Searching for the World's First Zero The Origin of the Number Zero. Zeno's paradoxes. The Story of Mathematics - Sumerian/Babylonian Mathematics. Predicting Reactions. There are five different types of reactions possible in the reactions section in the AP Test: DRY MIX Experimental Variables Acronym. Molecular Geometry.

Molecular Geometry. Quantum Consciousness. Hinduism & Quantum Physics. Vedic Mathematics. FAQ on Vedic Mathematics. Holism in science. Six degrees of separation. Coincidence. Science On a Sphere. Temperature World. Circular polarization. Electron Appears Spherical, Squashing Hopes for New Physics Theories. Dimension-Cruncher: Exotic Spheres Earn Mathematician John Milnor an Abel Prize. Ziman. Smith chart. Voronoi diagram. Material conditional. Create a topographic profile. Impact: Earth! The Electromagnetic Spectrum. TrendCompass. eXplorerDemo.

Monophyletic, Polyphyletic, & Paraphyletc Taxa. Reconstructing the tree of life. Buffalo Ontology Site. History of Medicine. Dramatic diagrams of cell biology and atomic structure belong in a beautiful textbook. Welcome to Reactome Pathway Database. Quick Graph review: Best graphing calculator app for iPhone and iPad. Themes & Topics. Mathematical Background.