Files can be lost accidentally in many different ways. Even if they are not lost completely, they can occasionally become corrupted. If a file is severely corrupted it may be unusable, but even subtle corruption may introduce errors which go unnoticed while affecting the outcome of your research.
See storage and servers (log in to intranet) for further information including information about backing up data held on user controlled computers and file servers.
Things to think about
Regular backups: (ideally automated) to several different locations will ensure that if one copy is lost or corrupt, you can easily get it back. When deciding how often to back up, think about the maximum number of days' work you would be prepared to lose.
Checksum tools: A checksum is a file's digital signature, which can then be used to detect unexpected changes in their contents.
In many cases, you may wish to restrict access to your data to a specific list of individuals. This might be because it is commercially sensitive to you or an industrial partner, or includes sensitive personal information covered by the Data Protection Act.
Legal requirements: You may be under legal and/or contractual obligations to protect your data. If you're not sure, you can discuss this with the university's Policy, Compliance & legal Support Officers within the Research and Knowledge Transfer Office(log in to intranet to view), who can give you advice on your collaboration or consortium agreements and laws such as the Data Protection Act.
Use of secure systems: One way to restrict access is to use a password-protected system. Commercial services such as Dropbox may be convenient, but are unlikely to provide sufficient protection against unauthorised access.
Secure passwords: Passwords are often the weak link in any secure system. Make sure you choose passwords that are long and difficult to guess. Writing them down is OK, as long as you protect your written-down password very well, just like you would with your house or car keys.
Encryption: You will sometimes need to send data to people who don't have access to your secure storage system. Encrypting a file before you send it via insecure means (e.g. email) ensures that the contents can only be read by someone who has the key.
often-overlooked aspect of data safety is ensuring that it remains usable.
Students and staff arrive and leave on a regular basis, and often it can seem
easier to repeat a whole set of expensive experiments rather than try to
understand data left behind by researchers who have left the university.
Things to think about
Documenting data: Record information about the structure and format of your data and the process you went through to obtain it. In some cases this can be stored in the data files themselves; if not, it can be stored in a "read me" document in the same folder as the data.
Using standards: Be aware of standard file formats and standard nomenclature (such as letters used for variables) used in your field. Consider using files in open formats so that they can be read by a variety of software.