Distance education, or distance learning, is a field of education that focuses on the pedagogy and andragogy, technology, and instructional systems design that aim to deliver education to students who are not physically "on site". Pedagogy (ˈpɛdəgɒdʒi or paedagogy is the Art or Science of being a Teacher. Andragogy is the process of engaging adult learners in the structure of the learning experience Rather than attending courses in person, teachers and students may communicate at times of their own choosing by exchanging printed or electronic media, or through technology that allows them to communicate in real time. Distance education courses that require a physical on-site presence for any reason including the taking of examinations is considered to be a hybrid or blended course or program.
Distance education dates back to at least as early as 1728, when "an advertisement in the Boston Gazette. . . [named] 'Caleb Phillips, Teacher of the new method of Short Hand" was seeking students for lessons to be sent weekly.  Modern distance education has been practiced at least since Isaac Pitman taught shorthand in Great Britain via correspondence in the 1840s. Sir Isaac Pitman ( January 4 1813 &ndash January 12 1897) knighted in 1894 developed the most widely used system of Shorthand  The development of the postal service in the 19th century lead to the growth of Commercial correspondence colleges with nation-wide reach.
The University of London was the first university to offer distance learning degrees, establishing its External Programme in 1858. The University of London is a university based primarily in London, England, UK. The University of London External System (until recently the University of London External Programme) is the External degree granting division of the University  Another pioneering institution was the University of South Africa, which has been offering Correspondence Education courses since 1946. The largest distance education university in the United Kingdom is the Open University founded 1969. The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom, the UK or Britain,is a Sovereign state located Open University is also the name of other institutions See Distance education or the Open Universities category for a list In Germany the FernUniversität in Hagen was founded 1974. Germany, officially the Federal Republic of Germany ( ˈbʊndəsʁepuˌbliːk ˈdɔʏtʃlant is a Country in Central Europe. The FernUniversität in Hagen (Distance University of Hagen is the only state-run distance teaching University in Germany. There are now many similar institutions around the world, often with the name Open University (in English or in the local language), and these are listed below. English is a West Germanic language originating in England and is the First language for most people in the United Kingdom, the United States
Charles Wedemeyer of the University of Wisconsin at Madison is considered the father of modern distance education in America. From 1964-1968 the Carnegie Foundation funded Wedemeyer's Articulated Instructional Media Project (AIM) which brought in a variety of communications technologies aimed at providing learning to an off-campus population. According to Moore's recounting, AIM impressed the British who imported these ideas and used them to create the first Open University, now called United Kingdom Open University (UKOU) to distinguish it from other open universities which have emerged. Open University is also the name of other institutions See Distance education or the Open Universities category for a list UKOU was established in the late 1960s and used television and radio as its primary delivery methodologies, thus placing it in the forefront of applying emerging technologies to learning. It is fair to say that all "open universities" use distance education technologies as delivery methodologies. 
There are many private and public, non-profit and for-profit institutions offering courses and degree programs through distance education. Levels of accreditation vary; some institutions offering distance education in the United States have received little outside oversight, and some may be fraudulent diploma mills. Educational accreditation is a type of Quality assurance process under which services and operations of an educational institution or program are evaluated by an external body The United States of America —commonly referred to as the A diploma mill (also known as a degree mill) is an organization that awards Academic degrees and Diplomas with substandard or no academic study and without In many other jurisdictions, an institution may not use the term "University" without accreditation and authorisation, normally by the national government. Online education is rapidly increasing among mainstream universities in the United States, where online doctoral programs have even developed at prestigious research institutions. 
In the twentieth century, radio, television, and the Internet have all been used to further distance education. The Internet is a global system of interconnected Computer networks Computers and the Internet have made distance learning distribution easier and faster. A computer is a Machine that manipulates data according to a list of instructions. The Internet is a global system of interconnected Computer networks 
In 2006 the Sloan Consortium reported that more than 96 percent of the largest colleges and universities in the United States offered online courses and that almost 3. The United States of America —commonly referred to as the 2 million U. S. students were taking at least one online course during the fall 2005 term. 
The types of available technologies used in distance education are divided into two groups: synchronous and asynchronous. Synchronous technology is used in distance education lessons in which learning is occurring in different places but at the same time. Asynchronous technology is used in lessons in which learning is occurring in different places but also at different times.
Distance Education has traversed four to five 'generations' of technology in its history. Basic principle A traditional landline telephone system also known as "plain old telephone service" (POTS, commonly handles both signaling and audio information A videoconference (also known as a videoteleconference) is a set of interactive Telecommunication technologies which allow two or more locations to interact Voicemail (or voice mail voice-mail vmail or VMS, sometimes called messagebank) is a centralized system of managing Telephone messages for a large group Fax (short for facsimile, from Latin fac simile, "make similar" i Videotape is a means of recording images and sound onto Magnetic tape as opposed to movie film. The Compact Cassette, often referred to as audio cassette, cassette tape, cassette, or simply tape, is a Magnetic tape sound Radio is the transmission of signals by Modulation of electromagnetic waves with frequencies below those of visible Light. Television ( TV) is a widely used Telecommunication medium for sending ( Broadcasting) and receiving moving Images, either monochromatic These are print, audio/video broadcasting, audio/video teleconferencing, computer aided instruction, e-learning/ online-learning, computer broadcasting/webcasting etc. Yet the radio remains a very viable form, especially in the developing nations, because of its reach. In India the FM Channel is very popular and is being used by universities, to broadcast educational programs of variety on areas such as teacher education, rural development, programs in agriculture for farmers, science education, creative writing, mass communication, in addition to traditional courses in liberal arts, science and business administration. The increasing popularity of mp3 players, PDAs and Smart Phone has provided an additional medium for the distribution of distance education content, and some professors now allow students to listen or even watch video of a course as a Podcast . A smartphone is a Mobile phone offering advanced capabilities beyond a typical mobile phone often with PC -like functionality A podcast is a series of audio or Video digital-media files which is distributed over the Internet by syndicated Download Some colleges have been working with the U. S. military to distribute entire course content on a PDA to deployed personnel. 
One of the newest technologies for delivery of distance education is the 3D virtual world of the online community Second Life. Second Life ( abbreviated as SL) and its sister site Teen Second Life are Internet-based 3D Virtual Institutions reported to have used Second Life in instruction include Bloomsburg University, Princeton University, Rice University, University of Derby (UK), Vassar College, and the Open University (UK). Bloomsburg University of Pennsylvania, commonly referred to as Bloomsburg, BU, or Bloom is a public University located in Pennsylvania Princeton University is a private Coeducational research university located in Princeton, New Jersey. William Marsh Rice University (commonly called Rice University and opened in 1912 as The William Marsh Rice Institute for the Advancement of Letters Science and Art The University of Derby is a University in the city of Derby, England. Vassar College is a private Coeducational, liberal arts college situated in the town of Poughkeepsie, New York, USA. Open University is also the name of other institutions See Distance education or the Open Universities category for a list In at least one instance, an entire online course was conducted through Second Life . In 2007 Second Life started to be used for foreign language instruction . English (as a foreign language) has gained a presence through several schools, including the British Council, which has focused on the Teen Grid. The British Council is a Public Body of the United Kingdom Government which specialises in educational and development opportunities Teen Second Life is a version of Second Life reserved for teenagers running on the so-called "Teen Grid Spain’s language and cultural institute “Instituto Cervantes” has an island on Second Life.
There is also an increased use of WebEx as an online learning platform and classroom for a diverse set of education providers such as Fox School of Business for Templer University, Grades Grow, Minnesota State Colleges and Universities, and Sachem. WebEx Communications Inc is a Cisco company that provides on-demand collaboration online meeting Web conferencing and Video conferencing applications Webex is a Cisco Web Meetings and Collaboration Solution. The platform has worked for educational institutions because of real time collaboration using an interactive whiteboard, chat, and VOIP technology that allows audio and video sharing. In distance learning situations, while replacing the classroom with features, institutions have also looked for security features which are inherently strong in a Cisco powered collaboration environment. The downside is that Webex is not a free platform like WiZiQ or Moodle, and fees are paid per 'host' of a classroom or a meeting.
Distance education has had trouble since its conception with the testing of material. The delivery is fairly straightforward, which makes sure it is available to the student and he or she can read it at their leisure. The problem arises when the student is required to complete assignments and testing. Whether quizzes, tests, or examinations; Online courses have had difficulty controlling cheating because of the lack of teacher control. In a classroom situation a teacher can monitor students and visually uphold a level of integrity consistent with an institution's reputation. With distance education the student can be removed from supervision completely. Some schools address integrity issues concerning testing by requiring students to take examinations in a controlled setting. 
Assignments have adapted by becoming larger, longer, and more thorough so as to test for knowledge by forcing the student to research the subject and prove they have done the work. Quizzes are a popular form of testing knowledge and many courses go by the honor system regarding cheating. Even if the student is checking questions in the textbook or online, there may be an enforced time limit or the quiz may be worth so little in the overall mark that it becomes inconsequential. Exams and bigger tests may be harder to regulate. In smaller tests a professor may employ another computer program to keep all other programs from running on the computer reducing the possibility of help from the Internet.
Used in combination with invigilators, a pre-arranged supervisor trusted with over-looking big tests and examinations may be used to increase security. Many Midterms and Final examinations are held at a common location so that professors can supervise directly. Many of these examinations are still on the computer in which case the same program blocking software can be used. When the Internet became a popular medium for distance education many websites were founded offering secure exam software and packages to help professors manage their students more effectively.
An Instructional Media Selection Guide for Distance Learning, an official publication of the United States Distance Learning Association (http://www.usdla.org). Contains definitions of distance learning, distance eduation, distributed learning, and e-learning, as well a Taxonomy of Instructional Media and a section on blended learning. Free download available at: http://www.usdla.org/html/resources/2._USDLA_Instructional_Media_Selection_Guide.pdf