In the science of measurement, a standard is an object, system, or experiment that bears a defined relationship to a unit of measurement of a physical quantity. Standards are the fundamental reference for a system of weights and measures, against which all other measuring devices are compared. Historical standards for length, volume, and mass were defined by many different authorities, which resulted in confusion and inaccuracy of measurements. Modern measurements are defined in relationship to internationally-standardized reference objects, which are used under carefully controlled laboratory conditions to define the units of length, mass, electrical potential, and other physical quantities.

Primary measurement standards may be used strictly in measurement laboratories. Less precisely controlled working standards are used for calibration of industrial measurement equipment. Primary standards that define units may be inconvenient for everyday use, so working standards represent the primary definition in a form that is easier to use. For example, the definition of the "metre" is based a laboratory experiment combining the speed of light and the duration of a second, but a machine shop will have working standard gauge blocks that are used for checking its measuring instruments.

Standard may refer to:

Any norm, convention or requirement

John Neal (August 25, 1793–June 20, 1876), was most notably an author and art/literary critic. He was also a man of diverse talents and objectives, many of which were pioneering in his day. For example, he is credited as being the first American author to employ colloquialism in his writing, breaking with more formal traditions in literature. However, he was also undisciplined and often rambling, so despite its period significance, his literary work has drifted into obscurity. He was also an early women's rights advocate, prohibitionist, temperance advocate, opponent of dueling, accomplished lawyer, boxer, and architect.

Born in a yellow frame house on Free Street at the corner of South Street in Falmouth (now Portland, Maine) of Quaker parents, he attended school until the age of twelve whereupon he entered into business. For nine years he made a living as haberdasher, clerk, dry goods dealer, traveling penmanship tutor, and miniature artist, among other things, before entering law school in Baltimore, Maryland in 1815. Neal supported himself while in school by writing for local periodicals, and he helped found a literary society, The Delphian Club. Neal wrote for and eventually edited the journal the Delphians created—a short-lived but influential and admired monthly journal titled The Portico. In short time, he turned to novels and poetry, publishing some six novels and two epic poems (under the pseudonymous 'clubicular' name, "Jehu O'Cataract," a nickname given to him by the Delphians because of his rapid production). He was proud of the speed with which he threw off his volumes, often taking only a week to finish an entire novel. He wrote during this stage in his life that, "I shall write, as others drink, for exhilaration." Neal left for England in late 1823.