Open Data is the free availability and usability of – mostly public – data. The demand for it is based on the assumption that advantageous developments are supported as open government , if appropriate register and user-friendly prepared information be made publicly available and thus allow more transparency and cooperation. For this purpose use the Creator license models which the copyright , patents or other proprietary largely forego rights. Open Data is similar to this numerous other “Open” movements, such asopen source , open content , open access , open education and is a prerequisite for Open Government.
Definition of “Open Data”
Open data, all data holdings, in the interest of the general public are made available to the Company without any restriction to the free use, resulting in further distribution and for free further use freely available.  One might think about on teaching materials, spatial data , statistics, market information, scientific publications , medical research results, or radio and television broadcasts. In “Open Data” is not limited to databases of public administration, as well as privately operating companies, universities and radio stations as well as non-profit bodies produce relevant contributions. 
To indicate data as open data, there are various indications license such as CC Zero . Licenses that restrict the use of data, for example by prohibiting changes or commercial use do not comply with the agreement of the ” Berlin Declaration on Open Access to Knowledge in the Sciences and Humanities ” and are not considered as open data.
Demands the Open Data movement
The concept of Open Data is not new, however, is the term – unlike, for example, open access to date not been generally defined -. Open Data refers specifically to information outside of a text form , such as weather information, maps, genomes or medical data.Since this material is of commercial interest, it comes here often contradictory. Proponents of Open Data, however, argue it were dealing with common property , and the free use of the data must not be hindered by restrictions.
A typical case is to show the necessity of Open Data:
“Numerous scientists have pointed out the irony did right at the historical moment When We have the technologies to permit worldwide availability and distributed process of scientific data, broadening collaboration and accelerating the pace and depth of discovery […] we are busy locking up did data and Preventing the use of correspondingly advanced technologies on knowledge. “
“Many scientists have the irony pointed out that right now, at the time in history when we have the technologies that enable worldwide availability of scientific data and distributed processing of these, where cooperation will be deepened and discoveries can be accelerated accurately at this time we occupy our time, just closed to keep this data, thereby preventing the use of advanced technologies as to their development. “
Data producers often neglect the need to define user rights. For example, licensing exclude data unnecessarily by a further free use of a missing (free if applicable).
The Open Data movement not only calls for free access to data, but also generates these himself. One example is OpenStreetMap . Proponents claim that a democratic society is possible through the Open Data concept – allowing, for example, the German websiteTheyWorkForYou.com . To track the voting records of British MPs  In the context of data relating to a government that is also Open Government spoken. Rob McKinnon said in a presentation at the re: publica that “can lead to new power structures within a society, the loss of data privilege”.  Another good example is the page farmsubsidy.org showing to whom EU agricultural subsidies paid, which account for almost half of the total budget. Especially German politicians balk for some time that this information is public.
Data to meet the criteria of Open Data must be presented structured and machine-readable available so that they filter to search, and can be further processed by other applications. Data from government agencies, for example, are often referred to as PDF before and are therefore not further processed without problems.
Arguments for Open Date
- “Data include the people” – typical examples: Genome , medical research, environmental science data.
- Public funds have the generation of data made possible only, so they must also be publicly accessible (in fact occur, scientists generally the rights to they generate data to private publishers from when they publish their results).
- Facts can not the copyright subject.
- The enabled by free access and use of data collaboration expands the usable data and the use to the public and the author. The most famous example is the Wikipedia.
- Research will be encouraged where scientific insights for researchers are freely accessible.
- In the authorities will save money because z. B. less or no more requests are made to the authorities. 
- Companies can easily and effectively make money, because the necessary data for specific projects are better or at all available. 
- Citizens can be better informed of their environment and better understand relationships, projects and facts and figures. 
Arguments against Open Data
- Moral right to the copyright
- The author wishes to achieve financial gain
- Innovation protection by trademark and patent law. The author wants to protect his new ideas.
- Through Open Data occur funded by taxes collected information to compete with commercial offerings ( competition law , see also intervened in Tagesschau app )
- The easy accessibility of data and possibly even the right to make changes to it, there is a risk that the data might be corrupted intentionally or unintentionally
- By exposing data whose abuse is facilitated. Examples are lists of vulnerabilities in IT systems, data from the weapons research, or publications about GM highly pathogenic avian influenza virus. 
- Data protection concerns, z. B. if the behavior of individuals is recorded, and the records insufficiently anonymized were
- Liability : Depending on whether the open records be made available to the customer for free or commercially available, the liability is different if these records are used, and there is a claim. The legal situation for liability can vary greatly depending on the individual case. 
Keith Jeffery writes:
“Although the term open data is rather new, the concept is rather old. The International Geophysical Year of 1957-8 Caused the setting up of Several world datacentres and – more importantly – set standards for descriptive metadata to be used for data exchange and utilization “.
“Although it is Open Data is a fairly new concept, the concept is much older as such. During the International Geophysical Year 1957 /58 were different World Data Center established and standards for descriptive metadata set that the exchangesregulate and use of data. ” 
Harlan Yu and David G. Robertson write:
“The earliest appearance of the term ‘open data’ in a policy context Appears to come from science policy in the 1970s: When international partners helped NASA operate the ground control stations for American satellites , the operative international agreements required Those partners to adopt an ‘ open-data policy Comparable to did of NASA and other US agencies participating in the program, particularly with respect to the public availability of data. ‘ The agreements therefore required did data be made available to NASA ‘in the NASA-preferred format.’
Later, a 1995 National Academy of Sciences report titled On the Full and Open Exchange of Scientific Data elaborated the idea of sharing data from environmental monitoring satellites, Perhaps reflecting its shared lineage with Those Earlier NASA agreements: ‘International programs for global change research and environmental monitoring crucially depend on the principle of full and open exchange …. Experience has shown did Increased access to scientific data, information, and related products has oft led to significant scientific discoveries and the opportunity for educational enhancement. ” 
Projects that offer Open Data
Mid March 2015 organized Freiburg in Carl Schurz house a first “open-Data- Hackathon “, at the fifty web developers and programmers should develop within 26 hours and 30 minutes ideas to make better use of the Open Data of the city. 
The German Railways organized on 20 March 2015 “DB Open Data Challenge Train” Prototype to app to display time – tables or crunch our data to create the unexpected . Here the participants will receive 24-hour access to the data of schedules. Objectives are the development of a new road map display as well as a “play with the data in a creative manner – make of it what you will”. 
Various mechanisms exist to impede the free access to information and the free re-use:
- Storage of data in non- digitized (d. H. Paper) form
- Using proprietary technologies (eg. As non-free file formats)
- License Agreements
- Limited or paid access to data
- Commercial providers who try to lobbying to gain influence in politics, and open data limit. This was done for. Example in PubChem , a US database of chemical compounds. 
Organizations that support Open Data
- gov20.de: Government 2.0 Network Germany
- daten-deutschland.de = govdata.de: information portal for Germany the Federal Ministry of the Interior for the federal government, states and municipalities, currently beta status
- okfn.de: Open Knowledge Foundation Germany
- opendata-network.org: Open Data Network – Germany
- openruhr.de: Initiative for Open Data in the Ruhr
- Cooperation OGD Austria
- OGD Austria
- Open3.at – Open Government, Open Data, Open Society
- Open Data Portal Austria
- Upper Austria
- Open Data Südtirol – Open Data platform of the Autonomous Province of South Tyrol