FAIR Data: Interoperable

When choosing file formats for research data it's important to consider whether the format is: 

• Open & non-proprietary
• Ubiquitous
• Uncompressed or lossless

File formats that are open or non-proprietary will tend to retain a good chance of being remaining accessible, even if the software that created them is no longer available. Specialised proprietary formats used only by a niche set of users may present problems for future use. Formats which are ubiquitous or have become the default standard within a discipline, whether proprietary or not, are also more likely to be maintained into the future. This is important whether you plan on sharing and archiving your data at the end of you research project or whether you simply want the data to remain accessible by yourself and other researchers in your department. 

• Proprietary format: Photoshop .psd file
• Open format: .tiff image file

Formats that are compressed or 'lossy' are often smaller in file size but the data are compressed as part of the encoding process, resulting in a data essentially being thrown away.

• Lossy formats: .mp3 audio file, .jpeg image file
• Lossless formats: .wav audio file, .tiff image file

Things to consider when choosing a file format:

• How you plan to analyse your data
• Which software and file formats you and your colleagues have used in the past
• Any discipline specific norms or technical standards
• Whether file formats are at risk of obsolescence because of their dependence on a particular technology.
• Which formats are best to use for the long-term preservation of data
• Whether important information might be lost by converting between different formats
• The possibility of embedding metadata that describes content within the file itself, e.g. creator information, variable names and labels

Sometimes it is useful to store your data using one format for data collection and analysis and also in a more open or accessible format for sharing or archiving once your project is complete. If it is your intention to share your data our chosen Archive or Repository will likely have recommended file formats based on best practice within the disciplines they support.