Technology changes quickly and with that change, certain previously preferred file formats and media will stop being used in favor of other more advantageous ones - this is called obsolescence.
This is a concern when working with research data because we know that, as researchers, our current methods for creating, storing, and sharing data could potentially become obsolete and be replaced by new formats.
Physical devices and media have a lifespan. While devices we use for storing data have improved exponentially over the last twenty years, expect external hardware devices to have a lifespan of 3 - 5 years. Plan on migrating your files every few years if you use an external hard drive to prevent data loss!
|Type of Data||Recommended Formats||Acceptable Formats|
|Tabular data with extensive metadata
variable labels, code labels, and defined missing values
|SPSS portable format (.por)
delimited text and command ('setup') file (SPSS, Stata, SAS, etc.)
structured text or mark-up file of metadata information, e.g. DDI XML file
|proprietary formats of statistical packages: SPSS (.sav), Stata (.dta), MS Access (.mdb/.accdb)|
|Tabular data with minimal metadata
column headings, variable names
|comma-separated values (.csv)
tab-delimited file (.tab)
delimited text with SQL data definition statements
|delimited text (.txt) with characters not present in data used as delimiters
widely-used formats: MS Excel (.xls/.xlsx), MS Access (.mdb/.accdb), dBase (.dbf), OpenDocument Spreadsheet (.ods)
vector and raster data
|ESRI Shapefile (.shp, .shx, .dbf, .prj, .sbx, .sbn optional)
geo-referenced TIFF (.tif, .tfw)
CAD data (.dwg)
tabular GIS attribute data
Geography Markup Language (.gml)
|ESRI Geodatabase format (.mdb)
MapInfo Interchange Format (.mif) for vector data
Keyhole Mark-up Language (.kml)
Adobe Illustrator (.ai), CAD data (.dxf or .svg)
binary formats of GIS and CAD packages
|Textual data||Rich Text Format (.rtf)
plain text, ASCII (.txt)
eXtensible Mark-up Language (.xml) text according to an appropriate Document Type Definition (DTD) or schema
|Hypertext Mark-up Language (.html)
widely-used formats: MS Word (.doc/.docx)
some software-specific formats: NUD*IST, NVivo and ATLAS.ti
|Image data||TIFF 6.0 uncompressed (.tif)||JPEG (.jpeg, .jpg, .jp2) if original created in this format
TIFF other versions (.tif, .tiff)
RAW image format (.raw)
Photoshop files (.psd)
Adobe Portable Document Format (PDF/A, PDF) (.pdf)
|Audio data||Free Lossless Audio Codec (FLAC) (.flac)||MPEG-1 Audio Layer 3 (.mp3) if original created in this format
Audio Interchange File Format (.aif)
Waveform Audio Format (.wav)
|Video data||MPEG-4 (.mp4)
OGG video (.ogv, .ogg)
motion JPEG 2000 (.mj2)
|AVCHD video (.avchd)|
|Documentation and scripts||Rich Text Format (.rtf)
PDF/UA, PDF/A or PDF (.pdf)
XHTML or HTML (.xhtml, .htm)
OpenDocument Text (.odt)
|plain text (.txt)
widely-used formats: MS Word (.doc/.docx), MS Excel (.xls/.xlsx)
XML marked-up text (.xml) according to an appropriate DTD or schema, e.g. XHMTL 1.0
Open, non-proprietary file formats are in less danger from obsolescence.
Match the following types of research data to the file formats:
Images = .tif
.tif or TIFF is a more sustainable format for images. Some image formats can compress the image and lose some of the image information, the TIFF format helps avoid that.
Spreadsheets = .csv
.csv or Comma Separated Value is a plain text more sustainable format for spreadsheets or tabular data. Similarly to the text formats mentioned above, other tabular data formats like .xslx from Excel are proprietary and rely on specific software to read them.
Textfiles = .txt
.txt or plain text is much more sustainable for text based files. Other textual file formats like .docx from Microsoft Word include extra proprietary information and rely on specific software to read them.
Audio = .flac.
.flac or Free Lossless Audio Codec is a more sustainable format for audio files - though you may often see .wav and .mp3 also recommended.
 UK Data Service, "Recommended formats", University of Essex, University of Manchester and Jisc. Retrieved from https://www.ukdataservice.ac.uk/manage-data/format/recommended-formats