Editing Machine-readable medium and data

{{short description|Medium capable of storing data in a format readable by a machine}}
[[Image:EAN-13-ISBN-13.svg|thumb|ISBN represented as [[European Article Number|EAN-13 bar code]] showing both machine-readable bars and human-readable digits]]

In [[communication]]s and [[computing]], a '''machine-readable medium''' (or '''computer-readable medium''') is a [[recording medium|medium]] capable of storing [[Data (computing)|data]] in a format easily readable by a [[digital computer]] or a [[sensor]]. 
It contrasts with [[human-readable medium and data|''human-readable'' medium and data]].

The result is called '''machine-readable data''' or '''computer-readable data''', and the data itself can be described as having '''machine-readability'''.

==Data==
Machine-readable data must be [[structured data]].<ref>{{Cite web|url=http://opendatahandbook.org/glossary/en/terms/machine-readable/|title=Machine readable|website=opendatahandbook.org|access-date=2019-07-22}}</ref>

Attempts to create machine-readable data occurred as early as the 1960s. At the same time that seminal developments in machine-reading and natural-language processing were releasing (like [[Joseph Weizenbaum|Weizenbaum's]] [[ELIZA]]), people were anticipating the success of machine-readable functionality and attempting to create machine-readable documents. One such example was musicologist [[Nancy B. Reich]]'s creation of a machine-readable catalog of composer [[Jay Sydeman|William Jay Sydeman]]'s works in 1966.

In the United States, the OPEN Government Data Act of 14 January 2019 defines machine-readable data as "data in a format that can be easily processed by a computer without human intervention while ensuring no semantic meaning is lost."  The law directs U.S. federal agencies to publish public data in such a manner,<ref>{{Cite web|url=http://stratml.us/references/HR4174.htm#Agency_Responsibilities|title=HR4174|website=stratml.us}}</ref> ensuring that "any public data asset of the agency is machine-readable".<ref>{{Cite web|url=http://stratml.us/references/HR4174.htm#machine-readabilty|title=HR4174|website=stratml.us}}</ref>

Machine-readable data may be classified into two groups: human-readable data that is [[markup language|marked up]] so that it can also be read by machines (e.g. [[microformat]]s, [[RDFa]], [[HTML]]), and [[data file]] formats intended principally for processing by machines ([[Comma-separated values|CSV]], [[Resource Description Framework|RDF]], [[XML]], [[JSON]]). These formats are only machine readable if the data contained within them is formally structured; exporting a CSV file from a badly structured spreadsheet does not meet the definition.

''Machine readable'' is not synonymous with ''digitally accessible''. A digitally accessible document may be online, making it easier for humans to access via computers, but its content is much harder to extract, transform, and process via computer programming logic if it is not machine-readable.<ref>{{cite web|url=https://www.data.gov/developers/blog/primer-machine-readability-online-documents-and-data|title=A Primer on Machine Readability for Online Documents and Data|date=2012-09-24|work=Data.gov|first1=Jim|last1=Hendler|first2=Theresa A.|last2=Pardo|access-date=2015-02-27}}</ref>

[[Extensible Markup Language]] (XML) is designed to be both human- and machine-readable, and Extensible Stylesheet Language Transformation (XSLT) is used to improve the presentation of the data for human readability. For example, XSLT can be used to automatically render XML in [[Portable Document Format]] ([[PDF]]). Machine-readable data can be automatically transformed for human-readability but, generally speaking, the reverse is not true.

For purposes of implementation of the Government Performance and Results Act (GPRA) Modernization Act, the [[Office of Management and Budget]] (OMB) defines "machine readable format" as follows:  "Format in a standard computer language (not English text) that can be read automatically by a web browser or computer system. (e.g.; xml). Traditional word processing documents and portable document format (PDF) files are easily read by humans but typically are difficult for machines to interpret. Other formats such as extensible markup language ([[XML]]), ([[JSON]]), or spreadsheets with header columns that can be exported as comma separated values (CSV) are machine readable formats. As HTML is a structural markup language, discreetly labeling parts of the document, computers are able to gather document components to assemble tables of contents, outlines, literature search bibliographies, etc. It is possible to make traditional word processing documents and other formats machine readable but the documents must include enhanced structural elements."<ref>[https://bidenwhitehouse.archives.gov/wp-content/uploads/2018/06/a11.pdf OMB Circular A-11, Part 6], Preparation, Submission, and Execution of the Budget</ref>

==Media==
Examples of machine-readable media include magnetic media such as [[Disk storage|magnetic disk]]s, cards, [[magnetic tape|tapes]], and [[magnetic drum|drums]], [[punched card]]s and [[paper tape]]s, [[optical disc]]s, [[barcode]]s and [[Magnetic Ink Character Recognition|magnetic ink characters]].

Common machine-readable technologies include magnetic recording, processing [[waveform]]s, and [[barcode]]s. [[Optical character recognition]] (OCR) can be used to enable machines to read information available to humans. Any information retrievable by any form of energy can be machine-readable.

Examples include:

*[[Acoustics]]
*[[Chemical]]
**[[Photochemistry|Photochemical]]
*[[Electrical]]
**[[Semiconductor]] used in [[volatile memory|volatile]] [[Random access memory|RAM microchips]]
**[[Floating-gate transistor]] used in  [[NVRAM|non-volatile]] [[memory card]]s
**[[Transmission (telecommunications)|Radio transmission]]
*[[Magnetic storage]]
*[[Classical mechanics|Mechanical]]
** Tins And Swins
*** [[Punched card]]
*** [[Paper tape]]
****[[Music roll]]
*** [[Music box]] cylinder or disk
**Grooves  ''(See also: [[Audio storage|Audio Data]])''
*** [[Phonograph cylinder]]
*** [[Gramophone record]]
*** [[DictaBelt]] (groove on plastic belt) 
*** [[Capacitance Electronic Disc]]
*[[Optics]]
**[[Optical storage]]
*[[Thermodynamic]]

==Applications==

===Documents===
{{excerpt|Machine-readable document}}

===Catalogs===
{{excerpt|Machine-readable cataloging|template=-Technical}}

===Dictionaries===
{{excerpt|Machine-readable dictionary}}

===Passports===
{{excerpt|Machine-readable passport}}

==See also==
* [[Paper data storage]]
* [[Symmetric Phase Recording]]
* [[Open data]]
* [[Linked data]]
* [[Human-readable medium and data]]
* [[Semantic Web]]
* [[Machine-readable postal marking (disambiguation)|Machine-readable postal marking]]
{{wiktionary|machine-readable}}

==References==
{{Reflist}}
{{FS1037C}}

{{DEFAULTSORT:Machine-Readable Medium}}
[[Category:Computing terminology]]
[[Category:Storage media]]
[[Category:Optical character recognition]]


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