Wellcome Library FAQ on validation
Q: What does validation mean?
Digital material is susceptible to unauthorised change or can become corrupted. Validation is a means of giving a file a unique alpha numeric code, or 'key', (sometimes called a hash) that is unique to that file. If the file changes then the file and the key no longer match. Validation is a process of giving a file, or files, their unique keys, before sending them to the
Wellcome Library, so that when they arrive the files can be checked against their keys to ensure that the files haven’t changed. There are a number of freely available validation methodologies and tools.
Q: Why does the Library use validation?
A: Validation allows us to check that files haven't changed over time. It is a way of ensuring the authenticity of material we hold by helping us guard against inadvertent or unauthorised change.
Q: Does the Library validate my material only once?
A: No. We will periodically run validation checks against all material in our archive to ensure that the material continues to match the validation key that is associated with it. This allows us to continue to be sure that that all our material remains authentic.
Q: What happens if you migrate or normalise my material, won't the validation key change?
A: Yes, it will change. A change in a file will result in a change to the validation key. Over time the format in which digital material is held may become obsolete and no longer accessible. We may need to migrate material to more current formats to ensure that material continues to be accessible and viable into the future. A new validation key will be re-generated once we are
sure that your material retains its intellectual content and context. This will allow us to continue to periodically check material for authenticity.
Q: Could the Library collect my material from me and assign validation keys?
A: We may be able to collect but we can't assign keys for you.
Q: What do I have to do?
A: Ideally you to assign a validation key to each file you are transferring to the Library. If you have many files you could assign a single validation key to the all the files on a CD or disk etc as an easier way of working. You need to tell us the key or keys, the validation method, and the tool you used.
Q: Do I have to provide a validation key for material I deposit with the Library?
A: No. Validation keys can be assigned once material has arrived in the Library. Whilst we prefer you to use a validation key to check that what you sent to the Library arrived in an unmodified condition we don't insist on you using one. If you are unfamiliar with downloading and installing software from the internet or unfamiliar with applying a validation key then we
suggest you don't.
Q: Do you have preferred validation tools?
A: We don't have preferred tool and we don't provide recommendations for tools. We prefer to use the SHA-1 validation method, but will accept alternatives such as MD5.
Q: Where can I get help?
A: Talk to your IT department, IT staff or IT help desk if you have one.
Q: What if I don't have an IT department to help me?
A: Software tools to create validation keys are freely available on the internet. The internet also has resources explaining validation and the validation process. If you are uncomfortable with downloading and installing software on your computer don't worry about assigning validation keys.
Q: Where can I get further information?
A: The Library has produced a series of Frequently Asked Questions (FAQs) about working with digital material. We will be happy to send you copies of these. Alternately you are welcome to contact Library staff.
Q: Is there someone in the Library I can talk to?
A: Yes. There are two contacts at the Wellcome Library who are available to answer your questions:
Natalie Walters, Archivist - n.walters@wellcome.ac.uk
Dave Thompson, Digital Curator - d.thompson@wellcome.ac.uk
Phone +44 (0)20 7611 8888
FAQ 3 June 2007
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