|OER Handbook for educators|
|Adapt OER||Quality | OER Translation | Offline Versions | Accessibility | Perspectives|
"Offline" or "local" versions of OER are OER that can be used without being connected to the internet. Bandwidth is limited in many countries and there are places that have very little access to the internet or where internet access is prohibitively expensive, even in so-called "developed countries" like the United States (Associated Press, 2008). For educators in these areas, "offline" versions of OER are tremendously valuable.
Local copies of OER save on bandwidth costs and greatly increase the speed at which users can access the resources. Having a local copy of the materials also enables new ways of modification and collaboration in the local context. For example, copying a course from MIT OCW into a local wiki enables a teacher to assign students to update and modify the course materials to make them more locally relevant.
To enable offline access to your OER, make the OER (or as much of it as possible) available for download in a format that is convenient for re-use and modification, and under a license that permits adaptation.
Offline-ready resources include:
- Downloadable pictures, audio, and video files
- Text pages that can be understood without following embedded hyperlinks
- OER packaged in digital form according to open standards (e.g. for use in a local LMS).
Resources which require modification for offline use include:
- Streaming video and audio
- Flash-based resources that cannot be downloaded
- Text pages that require following some/all of the links to make sense
Methods to provide offline OER
There are a number of ways local copies of materials can be provided:
- Web-site mirror: A mirror is an (exact) copy of a website. Some popular web-sites are hosted on mirrors across the world to reduce the access times for users from different regions. Static mirrors are one-time snapshots of an existing website. Dynamic mirrors are usually "seeded" with a substantive amount of content copied from the original server, and then updated dynamically based on user requests when an internet connection is available. For example, if a user in the local network requests a web page that has not been copied to the local mirror, then it has to be downloaded from the international site. At the same time it is added to the local mirror, so that the next user accessing the page, will get the (now available) local copy, saving additional trips to the international server.
- Web proxy / cache: A proxy server acts as a "middleman" between a user and a resource. A proxy server can be used to filter access to unwanted resources (e.g., block users on a university campus from accessing music download sites), but it can also be used to direct users to local copies of web resources. This can be done in a way that is invisible to the user, who is not aware if she is accessing the original resource or seeing a local copy of it. The user types in the URL for the web site he or she is interested in, and the proxy server decides if the content is sent back from the local copy or has to be downloaded from the international server first.
- Printable resources: some OER sites provide features to generate resources in a printable format (such as PDF). This is most useful for educators with occasional access to be able to print copies for learners without access to the internet.
- Copying content: A labor intensive process of copying materials from websites into a local repository. This is the least attractive option for users interested only in accessing the materials, since it requires a great deal of customization to ensure that hyperlinks continue to work, and is unlikely to reproduce a user experience similar to accessing the original materials. However, if you want to modify and adapt materials, some form of copying into a different local system is generally required. Using some of the existing standards (described above) can make the process easier. For example, some courses from the MIT OpenCourseWare project can be downloaded as IMS Content Packages archives, which can then be imported into a local learning management system and modified there. A number of tools allow automatic downloading of web content for local hosting and can also make the process significantly faster (see for example: HTTrack, wget and curl).
- Mirror sites run by others: Finally, there is a possibility that the resources you are looking for already exist as mirror sites on a network in your country or region, which can usually improve access speeds (and depending on the way your internet service provider(ISP) charges for access, reduce cost). For example, in South Africa the Tertiary Education Network (TENET) hosts a mirror of MIT's OpenCourseWare repository. Access speeds to this local mirror are much faster from university networks in South Africa than to the original MIT site.
Typically, large repositories of OER (such as Connexions or MIT OCW) like to offer their pages as a collection in ZIP format. ZIP is a type of file that actually works more like a folder; it can contain several different files that can be expanded using a unzipping program. A ZIP file uses compression to make the ZIP file smaller than the size of all the files put together normally, making ZIP perfect for distribution over the internet. There are several different ZIP programs such as 7-Zip that you can use to unzip files in the ZIP format.
A simple way to test how well your OER works in an offline setting is by disconnecting a computer from the internet and trying use the OER. If it does not, others may have a hard time making an offline copy of your resource.
- ↑ http://www.httrack.com/
- ↑ http://www.gnu.org/software/wget/
- ↑ http://curl.haxx.se/
- ↑ http://www.tenet.ac.za/
- ↑ http://ocw.mit.edu
- ↑ http://www.7-zip.org/
Associated Press. (2008, April 4). Navajo Nation likely to lose internet service. Retrieved April 4, 2008, from http://www.cnn.com/2008/TECH/04/04/navajo.internet.ap/
Schmidt, P. (2007, November). "7.2 Local hosting of materials." UNESCO OER Toolkit Draft. WikiEducator. Retrieved March 21, 2008, from http://www.wikieducator.org/UNESCO_OER_Toolkit_Draft#Local_hosting_of_materials